文章
Miss Chen
2017年11月22日
Tomatoes (Lycopersicon esculentum) are tender plants that can't withstand a heavy frost, but slightly frosted plants may recover. Usually grown as annual plants, tomatoes can grow year round in U.S. Department of Agriculture plant hardiness zones 10 through 11. At 40 degrees Fahrenheit and lower temperatures, tomato plants' leaves, stems and fruits suffer damage, but you can help save the plants by protecting them from further frosts.
Saving Young Plants
Young tomato plants are especially vulnerable to cold weather. Signs of frost damage include soft and discolored stems and leaves, and sunken leaf spots that are tan to brown. The spots usually appear between leaf veins. If the damage isn't extensive -- affecting only leaves' outer edges for example, then the plants probably will recover. Move the plants to a frost-free area if they're in containers, and cover plants in the ground with sheets of fabric if more frosts threaten. If the stems below the lowest leaves are discolored and soft, then little hope exists for the plants. Discard them and immediately sow or buy new tomato plants for a crop that year.
Rescuing Mature Plants
You may be able to save mature tomato plants that suffered a late frost. The average annual last frost date is only a rough guide to when to expect the late frost, and sometimes late spring or early summer frosts catch gardeners by surprise. If your mature tomato plants have frost damage, inspect them carefully. Those that collapsed completely can't be saved, and you may have to rely on kind neighbors for homegrown tomato fruits that year. If, however, your mature plants are still standing, tidy them by removing their frost-damaged leaves. Pinch or prune them at the nearest point where healthy tissue begins. Wipe the blades of the pruning shears in rubbing alcohol before and after pruning to help prevent the spread of pests and diseases.
Protecting Them from Frosts
If your tomato plants survived a light frost, then keeping an eye on the weather forecast and protecting them the next time frost is expected should be worth the effort. Water the tomato plants' soil the evening before a frost, and cover the plants with newspapers, old bedsheets, fabric tarps, floating rows covers or a similar material before the sun sets. Spread the material over the tomato plants' stakes, and don't allow the material to touch the plants because touching reduces the level of frost protection. An option to protect young tomato plants is to wash and cut the tops off plastic milk containers and place the containers over the plants before the night's frost. Remove the containers the following morning when the frost has thawed; doing so will prevent the young plants from heating in the sun's rays.
Harvesting Tomatoes After a Frost
The growing season for tomato plants is a few short months in some areas of the United States, but you can harvest tomato fruits up to and just after the first fall frost. Tomato plants produce best when daytime temperatures are 70 to 75 F during the day and 65 to 68 F at night. At temperatures below 60 F, production slows or stops, and the plants don't grow or produce when temperatures are cold enough to develop frosts. After the first fall frost, harvest all the fruits. Cut off all the fruits' frost-damaged parts and eat the undamaged portions fresh, or save undamaged fruits to eat as green tomatoes or to allow to ripen. Green tomatoes will ripen when spread in a single layer in a dark, airy location where the temperature doesn't fall below 55 F. Fruits from a frosted tomato plant shouldn't be canned because they may be unsafe.
Saving Young Plants
Young tomato plants are especially vulnerable to cold weather. Signs of frost damage include soft and discolored stems and leaves, and sunken leaf spots that are tan to brown. The spots usually appear between leaf veins. If the damage isn't extensive -- affecting only leaves' outer edges for example, then the plants probably will recover. Move the plants to a frost-free area if they're in containers, and cover plants in the ground with sheets of fabric if more frosts threaten. If the stems below the lowest leaves are discolored and soft, then little hope exists for the plants. Discard them and immediately sow or buy new tomato plants for a crop that year.
Rescuing Mature Plants
You may be able to save mature tomato plants that suffered a late frost. The average annual last frost date is only a rough guide to when to expect the late frost, and sometimes late spring or early summer frosts catch gardeners by surprise. If your mature tomato plants have frost damage, inspect them carefully. Those that collapsed completely can't be saved, and you may have to rely on kind neighbors for homegrown tomato fruits that year. If, however, your mature plants are still standing, tidy them by removing their frost-damaged leaves. Pinch or prune them at the nearest point where healthy tissue begins. Wipe the blades of the pruning shears in rubbing alcohol before and after pruning to help prevent the spread of pests and diseases.
Protecting Them from Frosts
If your tomato plants survived a light frost, then keeping an eye on the weather forecast and protecting them the next time frost is expected should be worth the effort. Water the tomato plants' soil the evening before a frost, and cover the plants with newspapers, old bedsheets, fabric tarps, floating rows covers or a similar material before the sun sets. Spread the material over the tomato plants' stakes, and don't allow the material to touch the plants because touching reduces the level of frost protection. An option to protect young tomato plants is to wash and cut the tops off plastic milk containers and place the containers over the plants before the night's frost. Remove the containers the following morning when the frost has thawed; doing so will prevent the young plants from heating in the sun's rays.
Harvesting Tomatoes After a Frost
The growing season for tomato plants is a few short months in some areas of the United States, but you can harvest tomato fruits up to and just after the first fall frost. Tomato plants produce best when daytime temperatures are 70 to 75 F during the day and 65 to 68 F at night. At temperatures below 60 F, production slows or stops, and the plants don't grow or produce when temperatures are cold enough to develop frosts. After the first fall frost, harvest all the fruits. Cut off all the fruits' frost-damaged parts and eat the undamaged portions fresh, or save undamaged fruits to eat as green tomatoes or to allow to ripen. Green tomatoes will ripen when spread in a single layer in a dark, airy location where the temperature doesn't fall below 55 F. Fruits from a frosted tomato plant shouldn't be canned because they may be unsafe.
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文章
Miss Chen
2017年11月22日
You can plant more tomato plants (Lycopersicon esculentum) in a garden when you support them with stakes or wire cages than if you let them sprawl on the ground. Because tomatoes require a soil temperature of at least 60 degrees Fahrenheit to plant from seed, most gardeners transplant nursery seedlings. How far apart you space plants also depends on the type of tomato, because some varieties need more space.
Spacing and Tomato Varieties
Determinate tomato varieties eventually form a cluster of flowers at their tip and stop growing taller. They are easier to grow and control and their tomatoes ripen earlier. Indeterminate tomatoes, including nearly all older and heirloom varieties, grow larger vines with a larger, more flavorful crop of late-maturing tomatoes. Indeterminate cultivars need to be planted farther apart than determinate or dwarf cultivars. Most people treat tomatoes as annuals but they will technically grow as perennials in U.S. Department of Agriculture plant hardiness zones 9 through 11.
Spacing Staked Tomatoes
If you train your tomatoes to grow on stakes you'll get larger tomatoes and they'll ripen earlier, but you'll get fewer of them and they're more likely to suffer from sun scald. Plant staked tomatoes 2 feet apart in rows spaced 3 to 4 feet apart. Dwarf tomatoes will only need 12 inches between plants. To give yourself enough room to harvest tomatoes, space vigorous indeterminate cultivars 4 feet apart and space rows 5 to 6 feet apart.
Spacing Caged Tomatoes
Plant caged tomatoes 2 1/2 to 3 feet apart in rows separated by 4 to 5 feet. Determinate tomatoes are best suited to cages. Prune the plants so that they will have from three to five stems. Especially vigorous indeterminate tomatoes will require larger cages, fewer stems in each cage and more space between plants and rows.
Spacing Tomatoes in Intensive Gardens
Plants in intensive gardens are spaced so their centers are an equal distance from one another. Tomatoes are especially suited to intensive gardening because they can be trained to grow vertically on stakes, cages or trellises. Space tomatoes 12 to 18 inches apart in an intensive garden.
Spacing and Tomato Varieties
Determinate tomato varieties eventually form a cluster of flowers at their tip and stop growing taller. They are easier to grow and control and their tomatoes ripen earlier. Indeterminate tomatoes, including nearly all older and heirloom varieties, grow larger vines with a larger, more flavorful crop of late-maturing tomatoes. Indeterminate cultivars need to be planted farther apart than determinate or dwarf cultivars. Most people treat tomatoes as annuals but they will technically grow as perennials in U.S. Department of Agriculture plant hardiness zones 9 through 11.
Spacing Staked Tomatoes
If you train your tomatoes to grow on stakes you'll get larger tomatoes and they'll ripen earlier, but you'll get fewer of them and they're more likely to suffer from sun scald. Plant staked tomatoes 2 feet apart in rows spaced 3 to 4 feet apart. Dwarf tomatoes will only need 12 inches between plants. To give yourself enough room to harvest tomatoes, space vigorous indeterminate cultivars 4 feet apart and space rows 5 to 6 feet apart.
Spacing Caged Tomatoes
Plant caged tomatoes 2 1/2 to 3 feet apart in rows separated by 4 to 5 feet. Determinate tomatoes are best suited to cages. Prune the plants so that they will have from three to five stems. Especially vigorous indeterminate tomatoes will require larger cages, fewer stems in each cage and more space between plants and rows.
Spacing Tomatoes in Intensive Gardens
Plants in intensive gardens are spaced so their centers are an equal distance from one another. Tomatoes are especially suited to intensive gardening because they can be trained to grow vertically on stakes, cages or trellises. Space tomatoes 12 to 18 inches apart in an intensive garden.
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文章
Miss Chen
2017年11月22日
Though generally grown as warm-season annuals, prized for their fast growth and juicy, sweet fruit, tomatoes (Lycopersicon esculentum) are technically frost-tender perennials in U.S. Department of Agriculture plant hardiness zones 9 through 11. Wilting in a tomato plant can be a symptom of several problems. Perk up your droopy tomatoes so you can continue to enjoy the fruits of your labor.
Water, Water, Everywhere
Tomatoes are 90 percent water. Thus, dehydration can lead to significant fruit loss and stunted growth. If you notice a plant wilting and the soil is dry, drought stress is likely the chief culprit. Tomatoes typically need watering once every four days in light, sandy soil and once a week if grown in heavier soil. When watering tomatoes, always use enough water to moisten the soil to a depth of 8 to 10 inches. Deep watering encourages the plant to extend its roots farther into the soil, increasing plant vigor and lowering risks of future drought stress. To conserve soil moisture, consider spreading mulch around the base of the plants, but keep mulch from touching the stems.
Sprinkle Some Salt
It may sound unconventional, but salt may do the trick. If you notice wilting, stunted leaf development and yellowing, the tomatoes may be suffering from a magnesium deficiency. Epsom salt is a naturally rich source of magnesium and may boost tomato growth and make the plant greener and more lush. Mix a tablespoon of Epsom salt in a gallon of tap water, pour it into a spray bottle and mist the solution onto the tomato plants. Coat all exposed surfaces of the plant evenly.
Check for Pests
Tomato plants occasionally suffer from pest infestations, and this may cause plant stress, wilting, leaf drop and fruit loss. Common tomato pests that cause wilted foliage include aphids and whiteflies, which suck on the plant's juices. Aphids appear as little green, black, red or brown spots on the plant. Whiteflies, as their name implies, are tiny flies with a dusty white appearance that tend to group on the underside of leaves. Both pests can be managed by spraying tomato plants with a strong blast of water from a backyard garden hose. This dislodges and kills pests and can keep pest populations at a level low enough that they don't cause lasting harm to the tomatoes.
Or, try an insecticidal soap. Make your own at home by mixing 5 tablespoons of liquid dish soap in a gallon of water. Spray the soapy solution onto affected portions of the tomato plant. The solution kills aphids and whiteflies on contact. Repeat once a week as needed.
Fight Fungus
Inspect the wilted foliage. If you see brown or black growths on the leaves, the tomatoes may be suffering from a fungal infection. Such problems are best controlled and prevented with proper sanitation. Wipe a pair of pruning shears with rubbing alcohol to sterilize it, then snip off any affected stems and leaves that have mold or other fungal growths.
Once you remove diseased plant parts, prevent future disease by monitoring your tomato care practices. Change your watering practices to ensure you're only watering at the base of each tomato plant, since overhead irrigation and damp foliage makes leaves susceptible to disease. Always use mulch, as that prevents soil from splashing up on your tomatoes which can increase the risks of plant disease. Finally, the next time you plant tomatoes, plant them in a new section of your backyard and space them farther apart to ensure proper air circulation among the plants. Ideally, plants should be approximately 2 feet apart.
Water, Water, Everywhere
Tomatoes are 90 percent water. Thus, dehydration can lead to significant fruit loss and stunted growth. If you notice a plant wilting and the soil is dry, drought stress is likely the chief culprit. Tomatoes typically need watering once every four days in light, sandy soil and once a week if grown in heavier soil. When watering tomatoes, always use enough water to moisten the soil to a depth of 8 to 10 inches. Deep watering encourages the plant to extend its roots farther into the soil, increasing plant vigor and lowering risks of future drought stress. To conserve soil moisture, consider spreading mulch around the base of the plants, but keep mulch from touching the stems.
Sprinkle Some Salt
It may sound unconventional, but salt may do the trick. If you notice wilting, stunted leaf development and yellowing, the tomatoes may be suffering from a magnesium deficiency. Epsom salt is a naturally rich source of magnesium and may boost tomato growth and make the plant greener and more lush. Mix a tablespoon of Epsom salt in a gallon of tap water, pour it into a spray bottle and mist the solution onto the tomato plants. Coat all exposed surfaces of the plant evenly.
Check for Pests
Tomato plants occasionally suffer from pest infestations, and this may cause plant stress, wilting, leaf drop and fruit loss. Common tomato pests that cause wilted foliage include aphids and whiteflies, which suck on the plant's juices. Aphids appear as little green, black, red or brown spots on the plant. Whiteflies, as their name implies, are tiny flies with a dusty white appearance that tend to group on the underside of leaves. Both pests can be managed by spraying tomato plants with a strong blast of water from a backyard garden hose. This dislodges and kills pests and can keep pest populations at a level low enough that they don't cause lasting harm to the tomatoes.
Or, try an insecticidal soap. Make your own at home by mixing 5 tablespoons of liquid dish soap in a gallon of water. Spray the soapy solution onto affected portions of the tomato plant. The solution kills aphids and whiteflies on contact. Repeat once a week as needed.
Fight Fungus
Inspect the wilted foliage. If you see brown or black growths on the leaves, the tomatoes may be suffering from a fungal infection. Such problems are best controlled and prevented with proper sanitation. Wipe a pair of pruning shears with rubbing alcohol to sterilize it, then snip off any affected stems and leaves that have mold or other fungal growths.
Once you remove diseased plant parts, prevent future disease by monitoring your tomato care practices. Change your watering practices to ensure you're only watering at the base of each tomato plant, since overhead irrigation and damp foliage makes leaves susceptible to disease. Always use mulch, as that prevents soil from splashing up on your tomatoes which can increase the risks of plant disease. Finally, the next time you plant tomatoes, plant them in a new section of your backyard and space them farther apart to ensure proper air circulation among the plants. Ideally, plants should be approximately 2 feet apart.
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文章
Miss Chen
2017年11月22日
Tomatoes from your own plant taste so much better than anything you purchase at a grocery store. You do not need to have a garden, or even a plot of land, to grow a tomato plant. You can even grow tomatoes on your screened porch.
Growing Tomatoes in Containers
Growing tomato plants in containers that have drainage holes is often better than growing them in the ground. That is because you can make sure of the quality of the soil, the level of watering required and can monitor and eliminate pests.
Screened porches can be an ideal location for your tomato plants, particularly if you live in a region that gets intense heat during the summer, which tomatoes do not tolerate well. One of the most important considerations when contemplating growing your tomatoes on a screened porch is the amount and quality of sunlight the area receives. Tomatoes need at least six hours of sun per day. If your screened porch is on the shady side of your home or has wide, overhanging eaves that prevent sunlight from entering any part of your porch, your tomato plants will not flourish. The opposite is also true if your screened in porch receives too much hot, intense sunlight, such as at midday. Your tomatoes may wilt or become sunburned. In this case, you may need to partially shade your porch where your tomato plants will grow.
Another consideration deals with pollination so your plant will produce tomatoes. Tomato plants do not need bees and such to pollinate; each plant has both male and female flowers. But the plant does require that there is at least slight breezes or air movement to allow the pollen to travel from one flower to the other. If you are lacking in breezes, you can always gently shake your plants every day or so to simulate this.
Selecting the right variety of tomato can help in growing tomatoes successfully on your screened porch. The preferred type is called a patio tomato because they have been formulated to grow in containers and produce an abundance of fruit. But other varieties can also successfully be grown on your porch. From cherry tomatoes to the beefsteak variety, many types can be grown in containers. Visit your local garden center, describe your location, particularly the light, and what you want to use the tomatoes for, to a salesperson and let her assist you in selecting the right plants.
Growing Tomatoes in Containers
Growing tomato plants in containers that have drainage holes is often better than growing them in the ground. That is because you can make sure of the quality of the soil, the level of watering required and can monitor and eliminate pests.
Screened porches can be an ideal location for your tomato plants, particularly if you live in a region that gets intense heat during the summer, which tomatoes do not tolerate well. One of the most important considerations when contemplating growing your tomatoes on a screened porch is the amount and quality of sunlight the area receives. Tomatoes need at least six hours of sun per day. If your screened porch is on the shady side of your home or has wide, overhanging eaves that prevent sunlight from entering any part of your porch, your tomato plants will not flourish. The opposite is also true if your screened in porch receives too much hot, intense sunlight, such as at midday. Your tomatoes may wilt or become sunburned. In this case, you may need to partially shade your porch where your tomato plants will grow.
Another consideration deals with pollination so your plant will produce tomatoes. Tomato plants do not need bees and such to pollinate; each plant has both male and female flowers. But the plant does require that there is at least slight breezes or air movement to allow the pollen to travel from one flower to the other. If you are lacking in breezes, you can always gently shake your plants every day or so to simulate this.
Selecting the right variety of tomato can help in growing tomatoes successfully on your screened porch. The preferred type is called a patio tomato because they have been formulated to grow in containers and produce an abundance of fruit. But other varieties can also successfully be grown on your porch. From cherry tomatoes to the beefsteak variety, many types can be grown in containers. Visit your local garden center, describe your location, particularly the light, and what you want to use the tomatoes for, to a salesperson and let her assist you in selecting the right plants.
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文章
Miss Chen
2017年11月21日
Most corn plants yield one to two ears of corn, depending on the cultivar. Corn is an annual plant, so once the ears have been harvested, it will not produce more corn.
Early Varieties of Sweet Corn
Early maturing sweet corn varieties will on produce one ear of corn per plant.
Early-maturing sweet corn varieties start producing within 60 to 80 days after planting. These plants will produce only one ear of corn per plant. The quality of the ear will depend on various conditions, including temperature during pollination and water availability during growth.
Later Maturing Sweet Corn
LAter maturing varieties will produce two ears.
Later-maturing varieties of sweet corn will produce two ears, with the second ear being of inferior size and quality to the first. Mid-season and late-season varieties of sweet corn mature within 79 to 95 days after planting.
Field Corn Varieties
Field corn produces one to two ears per plant.
Field corn, which is produced for such items as corn oil and silage, produces one to two ears of corn per plant. Ear size is larger than that of sweet corn, but it is of poor quality. Some varieties of field corn can produce six to 10 small ears of corn per plant.
Early Varieties of Sweet Corn
Early maturing sweet corn varieties will on produce one ear of corn per plant.
Early-maturing sweet corn varieties start producing within 60 to 80 days after planting. These plants will produce only one ear of corn per plant. The quality of the ear will depend on various conditions, including temperature during pollination and water availability during growth.
Later Maturing Sweet Corn
LAter maturing varieties will produce two ears.
Later-maturing varieties of sweet corn will produce two ears, with the second ear being of inferior size and quality to the first. Mid-season and late-season varieties of sweet corn mature within 79 to 95 days after planting.
Field Corn Varieties
Field corn produces one to two ears per plant.
Field corn, which is produced for such items as corn oil and silage, produces one to two ears of corn per plant. Ear size is larger than that of sweet corn, but it is of poor quality. Some varieties of field corn can produce six to 10 small ears of corn per plant.
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文章
Miss Chen
2017年11月20日
Tomato plants (Solanum lycopersicum) are prized for their crimson, juicy fruit. You're not the only one who enjoys the taste of tomatoes. Various pests may attack and feed on the tomato plant's fruit and foliage, causing leaf loss, plant stress and potential fruit loss. Protect your garden from some of the most common pests that afflict tomato plants.
Psyllids
Psyllids are tiny yellow or green insects that congregate on the underside of tomato leaves and inject a poison into the leaves, turning the tomato plant's foliage yellow and purple. These pests rarely reach population levels that cause true damage; most gardeners simply dislike psyllids for aesthetic reasons.
If you choose to control and eradicate psyllids, make your own psyllid insecticide at home:
Step 1
Pour 1/2 ounce of liquid hand soap or liquid dish detergent into a reusable spray bottle.
Step 2
Add 2 quarts of water to the spray bottle.
Step 3
Mix thoroughly.
Step 4
Spray the soapy solution onto affected portions of the tomato plant, focusing on the underside of leaves where psyllids like to gather.
Step 5
Repeat once a week until psyllid activity subsides.
Flea Beetles
Flea beetles, another common tomato pest, are brown or black beetles that hop away from you when touched. The adult beetles eat small holes into the foliage of the tomato plant.
Cover the vegetable bed with a floating row cover to block out beetles and protect young tomato plants. A floating row cover is an ultralight, ultrathin landscaping sheet that keeps pests from reaching the underlying plants but still lets sunlight and water get through. Drape the row cover over the garden bed as soon as tomato seedlings emerge, and weigh down the edges of the sheet with rocks or with U-shaped garden pins.
If flea beetles have already arrived, a floating row cover will not help. Instead, dust all exposed surfaces of the tomato plants with food-grade diatomaceous earth. This all-natural powder is made from crushed diatoms. The powder's tiny, sharp edges kill flea beetles.
Hornworms
If you see large gray-green or green caterpillars crawling on your tomato plants, you have a tomato hornworm problem. This pest is a fast eater. In just a few days, the caterpillars can completely strip the entire tomato plant of its leaves and fruit.
Pick the hornworms off of the tomato plant by hand. This is a convenient, efficient and simple way to eradicate the problem. Crush the caterpillars or drop them into a bucket of soapy water to kill them.
If you prefer a hands-off approach, use an organic caterpillar insecticide made with Bacillus thuringiensis kurstaki. Bt is a natural bacterium that kills caterpillars when it gets ingested. Bt insecticides come in sprays and powders.
Follow all labeled guidelines for product-specific application instructions. For example, when using a Bt insecticide powder with 0.4365 percent Bt, apply at a rate of 2 ounces for every 50 feet of row planting, dusting the powder evenly on all exposed parts of the tomato plant.
Whiteflies and Aphids
Whiteflies and aphids suck on the sap of the tomato plant and can cause wilting and leaf loss. A common symptom for either pest is the presence of honeydew -- a sticky, shiny substance excreted by the insects when they're feeding.
Spray the tomato plant with a strong jet of water from a garden hose. This is often all that's required to knock the aphids and whiteflies off of the plant and kill them. Repeat once a week to keep pest populations low.
Stink Bugs
Last but not least on the tomato plant's most-wanted pest list are stink bugs. These shield-shaped beetles come in various colors, including brown and green. If touched, they let out a pungent odor, hence their name. Stink bugs feed on tomato fruits causing spotting and the inner tissue becomes spongy and white. The first sign of damage appears as tiny dark spots surrounded by discoloring that can turn yellowish or green as the fruit matures.
Handpick the stink bugs off of the tomato plant -- wear gloves if you want to avoid their trademark stench -- and crush the bugs or drop them into a bucket of soapy water. Alternatively, use a handheld vacuum to quickly suck the insects off of the affected plant. Remove the vacuum's dust bag, place it in a sealed plastic bag and toss it in your freezer for a couple days to kill the trapped stink bugs.
Psyllids
Psyllids are tiny yellow or green insects that congregate on the underside of tomato leaves and inject a poison into the leaves, turning the tomato plant's foliage yellow and purple. These pests rarely reach population levels that cause true damage; most gardeners simply dislike psyllids for aesthetic reasons.
If you choose to control and eradicate psyllids, make your own psyllid insecticide at home:
Step 1
Pour 1/2 ounce of liquid hand soap or liquid dish detergent into a reusable spray bottle.
Step 2
Add 2 quarts of water to the spray bottle.
Step 3
Mix thoroughly.
Step 4
Spray the soapy solution onto affected portions of the tomato plant, focusing on the underside of leaves where psyllids like to gather.
Step 5
Repeat once a week until psyllid activity subsides.
Flea Beetles
Flea beetles, another common tomato pest, are brown or black beetles that hop away from you when touched. The adult beetles eat small holes into the foliage of the tomato plant.
Cover the vegetable bed with a floating row cover to block out beetles and protect young tomato plants. A floating row cover is an ultralight, ultrathin landscaping sheet that keeps pests from reaching the underlying plants but still lets sunlight and water get through. Drape the row cover over the garden bed as soon as tomato seedlings emerge, and weigh down the edges of the sheet with rocks or with U-shaped garden pins.
If flea beetles have already arrived, a floating row cover will not help. Instead, dust all exposed surfaces of the tomato plants with food-grade diatomaceous earth. This all-natural powder is made from crushed diatoms. The powder's tiny, sharp edges kill flea beetles.
Hornworms
If you see large gray-green or green caterpillars crawling on your tomato plants, you have a tomato hornworm problem. This pest is a fast eater. In just a few days, the caterpillars can completely strip the entire tomato plant of its leaves and fruit.
Pick the hornworms off of the tomato plant by hand. This is a convenient, efficient and simple way to eradicate the problem. Crush the caterpillars or drop them into a bucket of soapy water to kill them.
If you prefer a hands-off approach, use an organic caterpillar insecticide made with Bacillus thuringiensis kurstaki. Bt is a natural bacterium that kills caterpillars when it gets ingested. Bt insecticides come in sprays and powders.
Follow all labeled guidelines for product-specific application instructions. For example, when using a Bt insecticide powder with 0.4365 percent Bt, apply at a rate of 2 ounces for every 50 feet of row planting, dusting the powder evenly on all exposed parts of the tomato plant.
Whiteflies and Aphids
Whiteflies and aphids suck on the sap of the tomato plant and can cause wilting and leaf loss. A common symptom for either pest is the presence of honeydew -- a sticky, shiny substance excreted by the insects when they're feeding.
Spray the tomato plant with a strong jet of water from a garden hose. This is often all that's required to knock the aphids and whiteflies off of the plant and kill them. Repeat once a week to keep pest populations low.
Stink Bugs
Last but not least on the tomato plant's most-wanted pest list are stink bugs. These shield-shaped beetles come in various colors, including brown and green. If touched, they let out a pungent odor, hence their name. Stink bugs feed on tomato fruits causing spotting and the inner tissue becomes spongy and white. The first sign of damage appears as tiny dark spots surrounded by discoloring that can turn yellowish or green as the fruit matures.
Handpick the stink bugs off of the tomato plant -- wear gloves if you want to avoid their trademark stench -- and crush the bugs or drop them into a bucket of soapy water. Alternatively, use a handheld vacuum to quickly suck the insects off of the affected plant. Remove the vacuum's dust bag, place it in a sealed plastic bag and toss it in your freezer for a couple days to kill the trapped stink bugs.
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文章
Miss Chen
2017年11月20日
Rosemary (Rosmarinus officinalis) can resist many pest and disease problems, but plants weakened or stressed may fall prey to problems. The shrub grows in U.S. Department of Agriculture plant hardiness zones 8 through 10, but it also thrives as a potted plant in any climate. Soil or site conditions are common problems, although pests and fungus can also kill rosemary. It can be difficult or even impossible to save rosemary once it begins to die, but quick diagnosis and treatment sometimes prove successful.
Winter Kill
Winter freezes can kill a rosemary shrub, but it may not become obvious until after the temperature begins to warm in spring. The evergreen sprigs begin losing their color, become dry and brittle, and eventually turn completely brown or yellow. (ref 3) Minor freeze damage only kills a few branches, allowing you to save the plant, while major damage kills the roots and plant entirely. Cut back the damaged branches to the nearest healthy wood using pruning shears disinfected with isopropyl alcohol. The healthy roots and remaining living branches will usually survive and put on new growth through spring and summer. Prevent future stress by growing the rosemary in a pot and overwintering it indoors, or by covering it with a frost blanket when short hard freezes are expected.
Water Stress
Locations that easily become wet or waterlogged slowly kill rosemary plants. Rosemary can tolerate more moisture in summer, but wet winter soil quickly kills the plant either by suffocating the roots or by freezing solid. Rosemary prefers well-drained soil and moderate moisture conditions. Dig up and transplant the shrub to a well-drained, full sun garden bed, or transplant it into a pot with bottom drainage holes. Water rosemary about once a week when there is no rainfall and when the top 1 to 2 inches of soil feels dry, providing no more than 1 inch of water at each irrigation.
Fungal Disease
Fungal issues typically go hand-in-hand with wet soil. Root and crown rot, caused by the Phytophthora spp. fungus, cause stunted growth or branch death. The rosemary sprigs yellow and dry out, while the base of the stem and roots become soft, mushy and produce a foul odor. Moving the rosemary to a site with better drainage and refraining from watering until after recovery may allow it to live if the roots aren't badly damaged, but most shrubs won't recover from root rot. Powdery mildew fungus, which forms as a white powder on the rosemary needles, favors dry conditions and warm temperatures between 60 and 80 degree Fahrenheit. Providing the rosemary with full, all-day sunlight and spraying the foliage with water early in the day to rinse away spores can minimize mildew issues. For extreme infections, cut out the mildewed branches with disinfected shears so the remaining healthy branches can recover.
Leaf and Stem Pests
Various pests feed on rosemary plants, including spittle bugs, aphids and whiteflies. Rosemary usually recovers from pest damage unless the infestation is severe or if the plant is already weakened by cold or water stress. Pear-shaped aphids feed on the underside of the stems. Spittle bugs leave behind a white, foamy residue that resembles spittle. Treat both by rinsing them off the rosemary with a sharp spray of water, or drench the plant with a ready-to-use insecticidal soap at five-day intervals until the pests are gone. Water sprays and soap products can also help control whiteflies. Spray the plants several times a day with water to discourage the flies and their larvae. Yellow sticky traps or reflective mulch spread around the rosemary may also minimize whitefly problems.
Chemical Damage
Premature needle death, yellowing of the needle tips or a general burned appearance may indicate chemical damage from herbicides, pesticides or improper fertilization. Herbicide drift, which occurs when the wind carries the spray beyond its intended target, causes leaf dieback or kills the entire plant. Pruning out the affected branches may allow the plant to recover if the chemicals haven't reached the roots. Excessive use of fertilizers can lead to the buildup of fertilizer salts in the soil, especially in container-grown plants. Watering the rosemary deeply so the excess moisture drains freely from the bottom of the pot at least once monthly during the summer helps flush out any excess salt.
Nutritional Deficiencies
Fertilizer is seldom necessary for a rosemary shrub, especially those grown in garden beds where the trace nutrients in the soil provide sufficient fertilization. Potted plants or those grown in exceptionally poor soil may be suffering from a nutrient deficiency if the plant grows slowly or develops stunted, pale yellow needles. An application of a general purpose fertilizer in early spring should provide enough nutrients to help the plant recover. Follow package instructions or mix 1/2 teaspoon of a soluble 24-8-16 blend with 1 gallon of water, and water the rosemary with the solution. Avoid applying fertilizer directly to the foliage because it can damage the needles.
Winter Kill
Winter freezes can kill a rosemary shrub, but it may not become obvious until after the temperature begins to warm in spring. The evergreen sprigs begin losing their color, become dry and brittle, and eventually turn completely brown or yellow. (ref 3) Minor freeze damage only kills a few branches, allowing you to save the plant, while major damage kills the roots and plant entirely. Cut back the damaged branches to the nearest healthy wood using pruning shears disinfected with isopropyl alcohol. The healthy roots and remaining living branches will usually survive and put on new growth through spring and summer. Prevent future stress by growing the rosemary in a pot and overwintering it indoors, or by covering it with a frost blanket when short hard freezes are expected.
Water Stress
Locations that easily become wet or waterlogged slowly kill rosemary plants. Rosemary can tolerate more moisture in summer, but wet winter soil quickly kills the plant either by suffocating the roots or by freezing solid. Rosemary prefers well-drained soil and moderate moisture conditions. Dig up and transplant the shrub to a well-drained, full sun garden bed, or transplant it into a pot with bottom drainage holes. Water rosemary about once a week when there is no rainfall and when the top 1 to 2 inches of soil feels dry, providing no more than 1 inch of water at each irrigation.
Fungal Disease
Fungal issues typically go hand-in-hand with wet soil. Root and crown rot, caused by the Phytophthora spp. fungus, cause stunted growth or branch death. The rosemary sprigs yellow and dry out, while the base of the stem and roots become soft, mushy and produce a foul odor. Moving the rosemary to a site with better drainage and refraining from watering until after recovery may allow it to live if the roots aren't badly damaged, but most shrubs won't recover from root rot. Powdery mildew fungus, which forms as a white powder on the rosemary needles, favors dry conditions and warm temperatures between 60 and 80 degree Fahrenheit. Providing the rosemary with full, all-day sunlight and spraying the foliage with water early in the day to rinse away spores can minimize mildew issues. For extreme infections, cut out the mildewed branches with disinfected shears so the remaining healthy branches can recover.
Leaf and Stem Pests
Various pests feed on rosemary plants, including spittle bugs, aphids and whiteflies. Rosemary usually recovers from pest damage unless the infestation is severe or if the plant is already weakened by cold or water stress. Pear-shaped aphids feed on the underside of the stems. Spittle bugs leave behind a white, foamy residue that resembles spittle. Treat both by rinsing them off the rosemary with a sharp spray of water, or drench the plant with a ready-to-use insecticidal soap at five-day intervals until the pests are gone. Water sprays and soap products can also help control whiteflies. Spray the plants several times a day with water to discourage the flies and their larvae. Yellow sticky traps or reflective mulch spread around the rosemary may also minimize whitefly problems.
Chemical Damage
Premature needle death, yellowing of the needle tips or a general burned appearance may indicate chemical damage from herbicides, pesticides or improper fertilization. Herbicide drift, which occurs when the wind carries the spray beyond its intended target, causes leaf dieback or kills the entire plant. Pruning out the affected branches may allow the plant to recover if the chemicals haven't reached the roots. Excessive use of fertilizers can lead to the buildup of fertilizer salts in the soil, especially in container-grown plants. Watering the rosemary deeply so the excess moisture drains freely from the bottom of the pot at least once monthly during the summer helps flush out any excess salt.
Nutritional Deficiencies
Fertilizer is seldom necessary for a rosemary shrub, especially those grown in garden beds where the trace nutrients in the soil provide sufficient fertilization. Potted plants or those grown in exceptionally poor soil may be suffering from a nutrient deficiency if the plant grows slowly or develops stunted, pale yellow needles. An application of a general purpose fertilizer in early spring should provide enough nutrients to help the plant recover. Follow package instructions or mix 1/2 teaspoon of a soluble 24-8-16 blend with 1 gallon of water, and water the rosemary with the solution. Avoid applying fertilizer directly to the foliage because it can damage the needles.
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文章
Miss Chen
2017年11月20日
Although some plants take well to division, or splitting, woody herbs such as rosemary (Rosmarinus officinalis cvs.) are propagated best with the layering technique. When layering, simply allow new plants to spring up alongside the "mother" plant until they are sturdy enough for you to "cut their cords" and move them to new locations.
Step 1
Choose one or two outer stems from the main rosemary plant, ensuring the stems look healthy and are tall. Spring is the best time to start this process, when the stems are most flexible and have plenty of time to root. If you want to layer more than one stem, then choose stems on each side of the main plant, and ensure each stem has room to grow.
Step 2
Mix one handful of compost and one handful of bonemeal with the top 4 to 6 inches of soil on each side of the rosemary plant. Each amended area should be a rectangular patch about 6 inches wide and 12 inches long, extending outward from the base of your selected stems.
Step 3
Dig a narrow trench about 2 inches deep in the center of the 12-inch-long section of amended soil. You can also judge the length for the trench by the general height of the stem that will lay in it, minus about 2 inches of the stem's leafy end.
Step 4
Strip a selected rosemary stem of most of its needlelike leaves, keeping the leaves on about 2 inches of the stem's tip. Use a small, sharp knife to slice the underside of the stem gently in several places, and dust the underside with hormone rooting powder. Disinfect the knife before and after its use by either spraying it with a household disinfectant or soaking its blade for five minutes in a solution that is one part bleach to three parts water. Air-dry the disinfected knife or rinse it with clean water and dry it with a clean cloth.
Step 5
Bend the stem gently down so that it lays flat against the bottom of the shallow trench. Do not press the last 2 inches of the stem's tip into the soil. That leafy part will remain above-ground. Use a landscape peg or U-shaped flexible wire at the midpoint of the stem to ensure the underside of the stem remains in contact with the ground.
Step 6
Fill the rest of the trench with the amended soil so that most of the stem is buried but its leafy end sticks above the soil.
Step 7
Repeat the process with each stem you want to layer to create a new plant. If you have several mature rosemary plants that you want to propagate, then repeat the process for the layering technique with them.
Step 8
Water the soil of the buried stems on a regular basis until the stems form rootlets. Although rosemary plants usually don't do well in moist soil, the baby plants will.
Step 9
Check for rootlets after several weeks by gently digging around the buried stems. It can take several months for the rosemary layering technique literally to take root. So be patient.
Step 10
Separate the young, well-established plants from their mother rosemary plant by slicing off the young plants near the base of the mature plant.
Step 11
Replant each young rosemary plant in its own container that has bottom drainage holes and is filled with potting soil. Alternatively, plant the young rosemary plants in a sunny place in your garden. When setting the young plants into containers or a garden bed, plant them at the same soil depth at which they previously grew. That depth usually is marked by a definite soil line on a plant's stem.
Step 1
Choose one or two outer stems from the main rosemary plant, ensuring the stems look healthy and are tall. Spring is the best time to start this process, when the stems are most flexible and have plenty of time to root. If you want to layer more than one stem, then choose stems on each side of the main plant, and ensure each stem has room to grow.
Step 2
Mix one handful of compost and one handful of bonemeal with the top 4 to 6 inches of soil on each side of the rosemary plant. Each amended area should be a rectangular patch about 6 inches wide and 12 inches long, extending outward from the base of your selected stems.
Step 3
Dig a narrow trench about 2 inches deep in the center of the 12-inch-long section of amended soil. You can also judge the length for the trench by the general height of the stem that will lay in it, minus about 2 inches of the stem's leafy end.
Step 4
Strip a selected rosemary stem of most of its needlelike leaves, keeping the leaves on about 2 inches of the stem's tip. Use a small, sharp knife to slice the underside of the stem gently in several places, and dust the underside with hormone rooting powder. Disinfect the knife before and after its use by either spraying it with a household disinfectant or soaking its blade for five minutes in a solution that is one part bleach to three parts water. Air-dry the disinfected knife or rinse it with clean water and dry it with a clean cloth.
Step 5
Bend the stem gently down so that it lays flat against the bottom of the shallow trench. Do not press the last 2 inches of the stem's tip into the soil. That leafy part will remain above-ground. Use a landscape peg or U-shaped flexible wire at the midpoint of the stem to ensure the underside of the stem remains in contact with the ground.
Step 6
Fill the rest of the trench with the amended soil so that most of the stem is buried but its leafy end sticks above the soil.
Step 7
Repeat the process with each stem you want to layer to create a new plant. If you have several mature rosemary plants that you want to propagate, then repeat the process for the layering technique with them.
Step 8
Water the soil of the buried stems on a regular basis until the stems form rootlets. Although rosemary plants usually don't do well in moist soil, the baby plants will.
Step 9
Check for rootlets after several weeks by gently digging around the buried stems. It can take several months for the rosemary layering technique literally to take root. So be patient.
Step 10
Separate the young, well-established plants from their mother rosemary plant by slicing off the young plants near the base of the mature plant.
Step 11
Replant each young rosemary plant in its own container that has bottom drainage holes and is filled with potting soil. Alternatively, plant the young rosemary plants in a sunny place in your garden. When setting the young plants into containers or a garden bed, plant them at the same soil depth at which they previously grew. That depth usually is marked by a definite soil line on a plant's stem.
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文章
Miss Chen
2017年11月19日
Rosemary is an aromatic evergreen herb used in cooking and scented cosmetic products. If you are already growing rosemary, you can start several new plants from your mother plant. The easiest way to regrow rosemary is by pruning and rooting cuttings.
Step 1
Fill a small planter with soil or a mix of soil and sand or vermiculite. You can also plant several cuttings together in one large planter, rather than rooting single stems in individual planters.
Step 2
Cut a soft stem just below a leaf or pair of leaves with a sharp knife or cutting shears. Choose a cutting no less than 3 inches – but up to 8 inches – from the tip.
Step 3
Strip the leaves from the bottom of the stem so the portion of the stem that will be planted is free of leaves.
Step 4
Dip the end of the stem in hormone rooting powder, if desired. Rooting powder is available in gardening supply stores and fortifies cuttings, but it is not necessary when rooting rosemary.
Step 5
Push the cutting into the soil and water it. Cover the plant with a plastic bag and leave it in a warm, sunny spot for about three weeks. Check roots by gently inverting the planter into your hand to see the underside of the soil.
Step 1
Fill a small planter with soil or a mix of soil and sand or vermiculite. You can also plant several cuttings together in one large planter, rather than rooting single stems in individual planters.
Step 2
Cut a soft stem just below a leaf or pair of leaves with a sharp knife or cutting shears. Choose a cutting no less than 3 inches – but up to 8 inches – from the tip.
Step 3
Strip the leaves from the bottom of the stem so the portion of the stem that will be planted is free of leaves.
Step 4
Dip the end of the stem in hormone rooting powder, if desired. Rooting powder is available in gardening supply stores and fortifies cuttings, but it is not necessary when rooting rosemary.
Step 5
Push the cutting into the soil and water it. Cover the plant with a plastic bag and leave it in a warm, sunny spot for about three weeks. Check roots by gently inverting the planter into your hand to see the underside of the soil.
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文章
Miss Chen
2017年11月19日
Rosemary plants are hardy and able to withstand many adverse conditions, including freezing weather and short periods of drought. It is possible to revive dried-out rosemary plants, depending on the overall condition of the plant.
Severity
Check the ends of the branches to determine the extent of damage. If the branches are thoroughly dried out, check the base of the trunk and roots. The rosemary plant needs to be replaced if the trunk or roots are dry and brittle.
Maintenance
If the plant is salvageable, carefully remove dried and dead leaves from it. Using a pair of sharp garden shears, trim the branches to remove all dried areas, without cutting into the live branches.
Conditions
Thoroughly water the rosemary plant and provide plenty of natural light. Water outdoor plants at their base until the soil is thoroughly moist. For container-grown rosemary, fill the container with fresh water and allow the soil to absorb the water. Repeat this several times, until the soil retains the moisture.
Severity
Check the ends of the branches to determine the extent of damage. If the branches are thoroughly dried out, check the base of the trunk and roots. The rosemary plant needs to be replaced if the trunk or roots are dry and brittle.
Maintenance
If the plant is salvageable, carefully remove dried and dead leaves from it. Using a pair of sharp garden shears, trim the branches to remove all dried areas, without cutting into the live branches.
Conditions
Thoroughly water the rosemary plant and provide plenty of natural light. Water outdoor plants at their base until the soil is thoroughly moist. For container-grown rosemary, fill the container with fresh water and allow the soil to absorb the water. Repeat this several times, until the soil retains the moisture.
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文章
Miss Chen
2017年11月19日
If you're interested in growing herbs, consider adding rosemary (Rosmarinus officianalis) to your list. Its delicate foliage is an attractive grayish-green and the plant fills the environment with its herbal aroma. Rosemary is generally easy to grow, but it might develop some problems if it's not given correct conditions or develops disease or pest problems. Catching these problems early can be essential to keep a rosemary plant in tip-top shape.
Not Enough Water
Rosemary grows outdoors year round in U.S. Department of Agriculture plant hardiness zones 8 through 10, but it also makes a good potted houseplant. Native to rocky and sandy Mediterranean regions, it requires excellent drainage to thrive. The plant only needs a modest amount of water and tolerates drought well once established. But like any plant, insufficient water can cause its foliage to wilt; if this happens, test the soil with your fingertip and, if it's dry several inches deep, water the plant well.
If you've caught the problem in time, the plant should revive and be undamaged. In future, water whenever the top few inches of soil feels dry to your fingertip.
Over-Watering and Fungus
A wilting rosemary plant can also indicate over-watering, a situation that tends to promote root rot. If the problem's not corrected, roots become slimy and soft, and stems wilt and eventually die back. Overly wet conditions can promote other fungal problems, such as powdery mildew, a disorder that causes fluffy white fungus to grow on stems and foliage; eventually, these plant parts dry up and die. In either case, trim away damaged parts of the plant, using shears to cut into healthy tissue below the damaged areas. Clean your blades with rubbing alcohol between cuts to prevent spreading disease.
If the plant's soil is wet and soggy, and some roots are affected, remove the plant from the soil, trim off damaged roots and replant the rosemary in fresh soil. You can also dust cut roots and stems with cinnamon, a natural fungicide, to help the plant recover. If all the plant's roots are affected, the problem probably can't be corrected and it's best to discard the plant.
Pest Problems
A rosemary plant can also attract several types of pests. These include aphids, which are soft-bodied greenish pests, and spittlebugs which leave a white, frothy liquid on the plant. Whiteflies, which are tiny whitish flying insects, might also appear. You might also see evidence of spider mites, microscopic pests that leave visible webs covering young leaves and stems. All these pests suck plant juices, causing foliage to wilt, dry up and eventually drop from the plant.
Control a minor infestation by washing them off the plant with a strong stream of water. If an infestation becomes severe, spray the rosemary plant with insecticidal soap until it's dripping wet. Dilute the soap at a rate of 5 tablespoons per gallon of water, and repeat the spray every week or two, as needed.
Preventing Problems
Planting rosemary in the garden in a spot that gets full sun and has excellent drainage helps prevent problems with fungus. Rosemary can spread to reach a width of 2 to 4 feet, so space multiple plants at least 2 feet apart to ensure good air circulation, which also helps prevent fungal growth. If your soil contains clay and tends to drain slowly, add some coarse sand at planting to improve its drainage, or plant rosemary in a raised bed.
If you grow rosemary indoors as a houseplant ensure the container has a drainage hole, keep it well-spaced from other plants and always let the plant drain well after watering; never let its pot sit in a water-filled saucer.
Whether indoors or in the garden, check plants often for pest problems, because these are best controlled when caught early, before damage is severe.
Not Enough Water
Rosemary grows outdoors year round in U.S. Department of Agriculture plant hardiness zones 8 through 10, but it also makes a good potted houseplant. Native to rocky and sandy Mediterranean regions, it requires excellent drainage to thrive. The plant only needs a modest amount of water and tolerates drought well once established. But like any plant, insufficient water can cause its foliage to wilt; if this happens, test the soil with your fingertip and, if it's dry several inches deep, water the plant well.
If you've caught the problem in time, the plant should revive and be undamaged. In future, water whenever the top few inches of soil feels dry to your fingertip.
Over-Watering and Fungus
A wilting rosemary plant can also indicate over-watering, a situation that tends to promote root rot. If the problem's not corrected, roots become slimy and soft, and stems wilt and eventually die back. Overly wet conditions can promote other fungal problems, such as powdery mildew, a disorder that causes fluffy white fungus to grow on stems and foliage; eventually, these plant parts dry up and die. In either case, trim away damaged parts of the plant, using shears to cut into healthy tissue below the damaged areas. Clean your blades with rubbing alcohol between cuts to prevent spreading disease.
If the plant's soil is wet and soggy, and some roots are affected, remove the plant from the soil, trim off damaged roots and replant the rosemary in fresh soil. You can also dust cut roots and stems with cinnamon, a natural fungicide, to help the plant recover. If all the plant's roots are affected, the problem probably can't be corrected and it's best to discard the plant.
Pest Problems
A rosemary plant can also attract several types of pests. These include aphids, which are soft-bodied greenish pests, and spittlebugs which leave a white, frothy liquid on the plant. Whiteflies, which are tiny whitish flying insects, might also appear. You might also see evidence of spider mites, microscopic pests that leave visible webs covering young leaves and stems. All these pests suck plant juices, causing foliage to wilt, dry up and eventually drop from the plant.
Control a minor infestation by washing them off the plant with a strong stream of water. If an infestation becomes severe, spray the rosemary plant with insecticidal soap until it's dripping wet. Dilute the soap at a rate of 5 tablespoons per gallon of water, and repeat the spray every week or two, as needed.
Preventing Problems
Planting rosemary in the garden in a spot that gets full sun and has excellent drainage helps prevent problems with fungus. Rosemary can spread to reach a width of 2 to 4 feet, so space multiple plants at least 2 feet apart to ensure good air circulation, which also helps prevent fungal growth. If your soil contains clay and tends to drain slowly, add some coarse sand at planting to improve its drainage, or plant rosemary in a raised bed.
If you grow rosemary indoors as a houseplant ensure the container has a drainage hole, keep it well-spaced from other plants and always let the plant drain well after watering; never let its pot sit in a water-filled saucer.
Whether indoors or in the garden, check plants often for pest problems, because these are best controlled when caught early, before damage is severe.
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文章
Miss Chen
2017年11月19日
Rosemary (Rosmarinus officinalis) is generally easy to grow, but sometimes it can have problems. To track down the cause of yellowing leaves on a rosemary plant, check which leaves are yellow. If only some of the leaves are yellow, the problem may be different than if all are yellow. Also check if the leaves are completely yellow or if they have a speckled appearance, which may provide another clue. Proper care of your rosemary plant may be able to save it. If not, knowing what the problem was can help you to have a healthy plant next time.
Nutrient Deficiency
A lack of necessary nutrients can cause a rosemary plant to have yellow leaves. The most common cause of yellow leaves is a lack of iron. The problem may also be caused by insufficient nitrogen, zinc or manganese.
If the problem starts on young leaves and spreads to the old ones, it's likely an iron deficiency. If the first leaves to turn yellow are the oldest ones, it could be nitrogen, zinc or manganese that's missing.
What your rosemary plant most likely needs to correct nutrient deficiency is fertilizer. Add fertilizer every month or two while the plant is growing, but no more than one or two times during winter dormancy. Use a basic water-soluble fertilizer such as 20-20-20 with micronutrients and mix 1 teaspoon of fertilizer with 1 gallon of water.
If the soil pH is too high, iron may be present in the soil but your rosemary won't be able to use it. Check the soil pH with a test kit or pH probe. If your soil pH is 7.0 or higher it is too alkaline.
Other imbalances that can cause trouble with the uptake of iron include too much copper, phosphorous, zinc, calcium or manganese. Too little potassium in the plant and too little iron in the soil will also turn leaves yellow. Repot houseplants to resolve such problems. For outdoor rosemary, use a soil test kit and then follow the label's recommendations for the results you get.
Root Rot and Water Problems
While rosemary grows outdoors in U.S. Department of Agriculture plant hardiness zones 8 through 10, you can also grow it as a houseplant. Root rot is the most common reason for a yellowing houseplant. If your plant has this condition you'll see stunted yellow leaves as well as overall stunted growth. Rosemary prefers dry soil, and too much water can trigger root rot.
Take a look at the roots by carefully removing the plant from its pot and exposing the roots. Plants with root rot will have at least some black roots and the roots will look slimy. Healthy roots are white and firm. If only a few roots have rot, you may be able to save the plant by increasing drainage and cutting back on watering. Allow the plant to dry out completely between waterings, and don't let it sit in a tray of water at any time.
Spider Mites
If spider mites are feeding on your rosemary, the leaves may be spotted with yellow. If you look closely you may also see webs where the leaves join the stems. Left untreated, these pests can kill your plant. Set your plant in the bathtub or take it outside and wash it down with a forceful spray of water to remove many of the spider mites. Repeat this each week until the problem is gone. Make sure your rosemary isn't getting too dry between waterings, which can increase the chances of spider mite problems.
Improper Lighting
Rosemary plants need full sun, about six to eight hours a day, and indoor plants require plenty of supplemental light. If your plant gets inadequate light it may struggle to survive. The lower leaves on the plant will turn yellow and drop off.
To prevent yellowing and other light-related problems, set your rosemary in a sunny south- or west-facing window where it gets enough sunlight. Supplement as needed with a grow light or standard fluorescent lighting. Place the fluorescent lights about 6 inches above the rosemary and leave them on about 14 hours a day. Use a timer to automate the light turning on and off.
Nutrient Deficiency
A lack of necessary nutrients can cause a rosemary plant to have yellow leaves. The most common cause of yellow leaves is a lack of iron. The problem may also be caused by insufficient nitrogen, zinc or manganese.
If the problem starts on young leaves and spreads to the old ones, it's likely an iron deficiency. If the first leaves to turn yellow are the oldest ones, it could be nitrogen, zinc or manganese that's missing.
What your rosemary plant most likely needs to correct nutrient deficiency is fertilizer. Add fertilizer every month or two while the plant is growing, but no more than one or two times during winter dormancy. Use a basic water-soluble fertilizer such as 20-20-20 with micronutrients and mix 1 teaspoon of fertilizer with 1 gallon of water.
If the soil pH is too high, iron may be present in the soil but your rosemary won't be able to use it. Check the soil pH with a test kit or pH probe. If your soil pH is 7.0 or higher it is too alkaline.
Other imbalances that can cause trouble with the uptake of iron include too much copper, phosphorous, zinc, calcium or manganese. Too little potassium in the plant and too little iron in the soil will also turn leaves yellow. Repot houseplants to resolve such problems. For outdoor rosemary, use a soil test kit and then follow the label's recommendations for the results you get.
Root Rot and Water Problems
While rosemary grows outdoors in U.S. Department of Agriculture plant hardiness zones 8 through 10, you can also grow it as a houseplant. Root rot is the most common reason for a yellowing houseplant. If your plant has this condition you'll see stunted yellow leaves as well as overall stunted growth. Rosemary prefers dry soil, and too much water can trigger root rot.
Take a look at the roots by carefully removing the plant from its pot and exposing the roots. Plants with root rot will have at least some black roots and the roots will look slimy. Healthy roots are white and firm. If only a few roots have rot, you may be able to save the plant by increasing drainage and cutting back on watering. Allow the plant to dry out completely between waterings, and don't let it sit in a tray of water at any time.
Spider Mites
If spider mites are feeding on your rosemary, the leaves may be spotted with yellow. If you look closely you may also see webs where the leaves join the stems. Left untreated, these pests can kill your plant. Set your plant in the bathtub or take it outside and wash it down with a forceful spray of water to remove many of the spider mites. Repeat this each week until the problem is gone. Make sure your rosemary isn't getting too dry between waterings, which can increase the chances of spider mite problems.
Improper Lighting
Rosemary plants need full sun, about six to eight hours a day, and indoor plants require plenty of supplemental light. If your plant gets inadequate light it may struggle to survive. The lower leaves on the plant will turn yellow and drop off.
To prevent yellowing and other light-related problems, set your rosemary in a sunny south- or west-facing window where it gets enough sunlight. Supplement as needed with a grow light or standard fluorescent lighting. Place the fluorescent lights about 6 inches above the rosemary and leave them on about 14 hours a day. Use a timer to automate the light turning on and off.
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文章
Miss Chen
2017年11月19日
Rosemary (Rosmarinus officinalis) originated in the Mediterranean region, where it adapted to warm temperatures, sandy soil and a dry environment. In warmer areas (zones 7 to 11) it is a perennial and can grow outdoors. Plant rosemary in a pot in colder areas (zones 6 to 2) so it can be brought inside during winter to protect it from the cold. Rosemary prefers slightly alkaline, sandy, well-drained soil so that the roots do not stay wet and it can live up to 20 years when well cared for.
Starting from a Cutting
The fastest way to get a rosemary plant started is from a cutting. Take the cutting from new growth on the parent plant, snipping about 2 to 4 inches from the end of the branch at the end of May or through the month of June. Trim off the bottom leaves and dip the end of the branch in rooting hormone before securing it in the lightly moistened potting soil. Cover the cutting and pot with a plastic bag to keep it in a warm, humid environment, between 60 to 70 degrees Fahrenheit and out of direct sunlight. The cuttings take about two to three weeks to develop roots and new growth, at which point they can be transplanted. Without rooting hormone, the cuttings take about eight weeks to develop roots.
Starting by Layering
Layering is another method used to propagate rosemary quickly, because the branch remains attached to the original plant and continues to receive nutrients from it. Use a branch that easily reaches the ground and remove leaves along a 1-inch section at that point. Secure it to the ground using a landscape pin and cover the section stripped of leaves with dirt. The layered branch develops roots over the course of a few months, recognizable because new growth starts developing at the tip of the branch. At this point, cut the branch from the parent plant and move it to its new location, taking care not to disturb the roots too much.
Starting From Seed
Although it is possible to start rosemary from seed, it is not the recommended method because the germination rate is only about 15 to 30 percent. They can take up to three months to germinate, so start them well before the planting season. Plant the rosemary seeds in a light, sandy potting medium, placing them about 3 inches apart. Spread a thin layer of the potting soil over the seeds and spray them lightly with water to moisten the soil. Cover the seed trays or cups loosely with plastic wrap to keep them moist and place them in a warm area. Once the seedlings start sprouting, they require ample sunlight and continued warmth. Plant them in larger pots or outdoors once there is no threat of frost. Burpee recommends waiting until the seedlings are about 3 inches tall before replanting.
Growing Conditions
Rosemary requires at least six to eight hours of sun a day for optimal growth. The plants reach a mature height of 3 to 5 feet, on average, with a spread of 4 to 5 feet, depending on the exact growing conditions and the specific cultivar. The size and shape can be controlled with pruning. When planted in a pot, rosemary may require transplanting and trimming twice a year because it grows fairly quickly. Once the outdoor temperatures reach about 30 degrees Fahrenheit, move the rosemary indoors to a sunny location with southern exposure and good air circulation to prevent the development of powdery mildew.
Starting from a Cutting
The fastest way to get a rosemary plant started is from a cutting. Take the cutting from new growth on the parent plant, snipping about 2 to 4 inches from the end of the branch at the end of May or through the month of June. Trim off the bottom leaves and dip the end of the branch in rooting hormone before securing it in the lightly moistened potting soil. Cover the cutting and pot with a plastic bag to keep it in a warm, humid environment, between 60 to 70 degrees Fahrenheit and out of direct sunlight. The cuttings take about two to three weeks to develop roots and new growth, at which point they can be transplanted. Without rooting hormone, the cuttings take about eight weeks to develop roots.
Starting by Layering
Layering is another method used to propagate rosemary quickly, because the branch remains attached to the original plant and continues to receive nutrients from it. Use a branch that easily reaches the ground and remove leaves along a 1-inch section at that point. Secure it to the ground using a landscape pin and cover the section stripped of leaves with dirt. The layered branch develops roots over the course of a few months, recognizable because new growth starts developing at the tip of the branch. At this point, cut the branch from the parent plant and move it to its new location, taking care not to disturb the roots too much.
Starting From Seed
Although it is possible to start rosemary from seed, it is not the recommended method because the germination rate is only about 15 to 30 percent. They can take up to three months to germinate, so start them well before the planting season. Plant the rosemary seeds in a light, sandy potting medium, placing them about 3 inches apart. Spread a thin layer of the potting soil over the seeds and spray them lightly with water to moisten the soil. Cover the seed trays or cups loosely with plastic wrap to keep them moist and place them in a warm area. Once the seedlings start sprouting, they require ample sunlight and continued warmth. Plant them in larger pots or outdoors once there is no threat of frost. Burpee recommends waiting until the seedlings are about 3 inches tall before replanting.
Growing Conditions
Rosemary requires at least six to eight hours of sun a day for optimal growth. The plants reach a mature height of 3 to 5 feet, on average, with a spread of 4 to 5 feet, depending on the exact growing conditions and the specific cultivar. The size and shape can be controlled with pruning. When planted in a pot, rosemary may require transplanting and trimming twice a year because it grows fairly quickly. Once the outdoor temperatures reach about 30 degrees Fahrenheit, move the rosemary indoors to a sunny location with southern exposure and good air circulation to prevent the development of powdery mildew.
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