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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Mealybugs are a pest common to cacti and succulents. Greenhouse and windowsill assemblages are especially vulnerable to the critters. You can eliminate mealybugs temporarily, but they are difficult to eradicate completely, especially in large groupings of plants. Deal effectively with mealybugs and restore healthy environmental conditions in your cactus collection to prevent future infestations.
About Mealybugs Mealybugs are gray or light brown insects 2 to 3 millimeters long. They resemble woodlice. Mealybugs can accumulate around the base of a cactus or just beneath the soil around its growing point. An early sign of a mealybug problem is a secretion that resembles white fluff on the plant. This is where the bugs reproduce. Fallen needles may also indicate a mealybug presence. Squashed bugs leave red or green stains. Ants farm mealybugs for their sweet secretions; an ant problem near a cactus may be an indication of mealybugs.
Natural Remedies There are many effective nonchemical approaches to dealing with mealybugs. Experiment to find the best method for your cactus. Dab bugs and white fluff with denatured alcohol on a cotton swab to kill the insects. Repeat this treatment as often as is necessary to remove all bugs from the plant, checking it thoroughly once every three weeks. Fumigant smoke cones may be effective if used regularly, especially in large groupings of plants in a greenhouse. Alternatively, spray cactus with several drops of dish soap diluted in a cup of water. For a biological control, introduce a mealybug predator such as Cryptolaemus montrouzieri. Be aware that the effectiveness of biological controls for mealybugs in home settings can be low, as maintaining a balance of predators and pray can be difficult. Manage an ant problem to deter mealybug farming.
Chemical Remedies Systemic insecticides poison bugs that ingest the cactus’ sap. Human skin, however, may also absorb these poisons. Imidacloprid is effective against mealybugs and is lower in toxicity to animals than some other chemical treatments. Water plants with imidacloprid once every several months during active growth. To deal with a root infestation, immerse the cactus’s pot in a bucket containing insecticide and a few drops of dish soap. Let the plant dry completely after this treatment. Be sure that no mealybugs survive a chemical treatment to help deter the bugs from becoming resistant to insecticide.
Preventative Care Isolate a newly acquired cactus for two to three weeks to observe whether it contains mealybugs. Inspect all of your cactus plants regularly to intercept a mealybug infestation while it is small, before it spreads to nearby plants. Notice any dramatic changes in your cactus’s condition, such as discoloration or sudden limpness, as these may be signs of a mealybug problem that is not readily visible. Keep the area around your cactus clean and free of dried leaves and dropped flowers, as rotting organic matter provides an ideal home for a wide range of pests and diseases.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Crassula ovata is a succulent native to South Africa and is commonly called the Jade Plant or Money Plant. It has jade green, egg-shaped leaves and bears small pink or white flowers. The jade plant is a favorite indoor plant that can grow into a small tree or shrub up to 5 feet (1.5 m) tall, although it can be easily trained into bonsai form. It will grow outdoors in U.S. Department of Agriculture plant hardiness zone 10, but is better grown indoors in USDA zones below that where prolonged winter cold can kill it.
Problems With Growth Jade Plants grown in pots can become root bound and top heavy causing them to tip over easily. Repot in the spring every two to three years or when it becomes top heavy. If you repot to the same size pot, prune the roots and stems to develop a thick main trunk. Do not overwater until the plant is growing well in the new container.
Problems With Sun and Temperature A Jade Plant will grow in partial shade, but it needs sun to produce blooms. Overexposure to direct sun or heat can scorch the leaves. Do not put a Jade Plant behind glass in full sun. Too much heat can cause it to drop its leaves and the stems may begin to rot. Do not let its foliage touch cold window panes in the winter and protect it from drafts.
Watering Problems A Jade Plant will withstand dry periods and will develop root rot if you leave it in soggy soil. This is a particular problem for jades grown in pots. Water sparingly when it is actively growing in the spring and summer. Let the soil dry between watering. Do not water in the winter. Drought can cause stunted growth and leaves to develop spots and drop, eventually killing it. Pests Mealybugs that look like small white puffs of cotton commonly infect jade plants. Insecticidal soap may damage the plant; instead, wipe them off with a cotton swab dipped in alcohol.
Spreading Problems Although Crassula ovata is not listed on California’s list of noxious weeds, it spreads easily from leaves and pieces of stems that break off and grow. The Jade Plant grows wild in warmer wetlands and coastal areas and in many canyons near urban areas of Southern California. If you live in an area warm enough to grow it outdoors, ensure that you can contain its potential to spread.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Succulent plants store water in their tissue. That, by definition, is what makes it a succulent plant. Succulents use the water they store in their tissue to help them survive long, dry periods. Since cacti and other succulents as a general rule grow in dry places, they take up water through their roots very quickly and efficiently. On the other hand, they do not have the ability to quickly get rid of excess water. While this all works out fine in the wild, when csucculents are grown in cultivation, people can supply more water than the succulents needs. This is actually a common situation and the plants in cultivation look plump and happy compared to their habitat counterparts.
But the real problems start when people don’t just give their succulent more water than it needs, but more water than it can handle. This is overwatering. When a succulent is overwatered, it will swell up more and more and often times the cactus stem will become so saturated that it splits open in one or more places. While a succulent can usually recover from this, the other result of overwatering (especially when combined with cold temperatures) is rot. Sometimes just the roots will rot off, but often times the whole plant will turn to mush.
Treatment The first thing to do with an overwatered cactus or other succulent is stop watering it! In most cases, repotting would also be a good idea. When the plant is unpotted, you can let it stay unpotted to dry out for a week or two and then repot it. If the plant body has split in any place, the damage is permanent and there is nothing you can do but let it scar over. If the plant has started to rot, saving the plant will depend on how far the rot has set in.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Jade Plant (Crassula ovata) are a classic houseplant, especially for the neglectful home owner. It prefer bright light and occasional water in the warm season, but other than that the plants are fairly self-sufficient. In good conditions, you may still find white spots on Jade Plant leaves; but if the plant’s overall health is good, you should not worry too much. What causes white spots on Jade Plant? It may be a natural phenomenon or a bit of a fungal disease, but either way, there are easy methods to define and deal with the problem.
What Causes White Spots? The few times I have discovered white spots on my Jade Plant, I simply rubbed them off lightly and the plant was no worse for wear. The actual cause of the white spots on Jade Plant leaves might be powdery mildew, or even a condition where the plant stores salts and “sweats” the excess out through its leaves. One cause has a quick fix and the other requires some cultural adjustment and treatment. Both are really not all that harmful to your plant and learning how to get rid of white spots on Jade Plants is a matter of some quick steps.
Powdery Mildew Most gardeners are familiar with powdery mildew. It occurs when there is low light, improper circulation, cooler temperatures and excess humidity. Overhead watering leaves foliage damp, which in winter months tends to stay moist for a long period. This promotes the formation of fungal spores that cause powdery mildew. Avoid overhead watering and use a fan to increase circulation. Pinch off affected foliage and discard it. A solution of baking soda and vinegar is how to get rid of white spots on jade plants with powdery mildew. Spray on the leaves but ensure the leaves dry within a few hours.
Excess Salts All plants uptake water through their roots with a few rare exceptions. Jade Plants store water in their fleshy leaves, which makes them ideal species in arid zones. They capture infrequent rainwater and store it until they need it much like a squirrel hoarding nuts. This gives the leaves their plump appearance. Rain and ground water alike capture salt from the air and soil. When you water with a salty solution, the trapped moisture will go through the leaves during transpiration and the evaporated moisture will leave a salt residue on the leaf. Therefore, your Jade Plant has white spots on the surface of the pads. A soft, lightly moist cloth can wipe these away easily and restore the appearance of the foliage.
Other Reasons for White Spots Jade Plants often get a condition called Oedema, where the roots take up water faster than the plant can use it. This causes corky blisters to form on the foliage. Reducing water should prevent the condition, but the blisters will remain. Rarely, you may find a Jade Plant has white spots which are actually insects. Mealybugs have a whitish silver fuzzy exterior. If your white spots are moving under close observation, take action and seclude the Jade Plant from other plants.
The spots may also be a variety of scale with silvery bodies. Both can be conquered with a systemic insecticide formulated for houseplants or by dabbing them with a 70 percent solution of rubbing alcohol. Jade Plants are not usually prone to insect infestations, but if you put the plant outdoors for the summer, take a good look at it before bringing it indoors and infecting your other flora.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Agave americana, commonly called the Century Plant, is a succulent desert plant native to Mexico. It can grow outdoors year-round in U.S. Department of Agriculture plant hardiness zones 8 to 10. The largest of the Agaves, mature plants range from 5 to 7 feet (1.5 to 2.1 m) tall with 8- to 12-foot (20 to 30 cm) spreads. Century Plant makes a dramatic accent plant with its blue or blue-gray leaves, black spines and showy, yellow-green flowers. Despite its renowned hardiness, Century Plant can still suffer from a few cultural, disease and pest problems.
Cultural Problems Century Plant can tolerate various cultural conditions as long as it is planted in fast-draining soils. Poor-draining soils make the plant susceptible to the fungal pathogens that cause root rot. This Agave can survive down to 15 degrees Fahrenheit (-15 degrees Celsius), but the broad, fleshy leaves will suffer from freeze damage if the temperature drops below freezing for several hours. Freeze-damaged tissue turns black, dries out and looks unsightly. The damage can’t be repaired, but most Century Plants will recover. Prevent freeze damage by covering the plant with a light, cotton sheet when your area is expecting a freeze.
Diseases Although Century Plant isn’t associated with any serious disease problems, root rot can be problematic in poor-draining or overly moist soils. Root rot causes wilting, stunted growth and discolored leaves. Unfortunately, this fungal infection cannot be treated once it occurs. Anthracnose is another occasional problem that occurs when fungal pathogens thrive in overly moist soil conditions. This disease causes lesions to form on the leaves, with red or orange spore masses developing inside the sores. Remove any anthracnose-infected plant tissue promptly to prevent the disease from spreading.
Pest Problems For the most part, Century Plant doesn’t have serious pest problems, but there is one exception. Root rot typically goes hand-in-hand with agave snout weevil infestations. Adult females chew through to the base of the plant to lay their eggs in the infected plant tissue. The larvae hatch and burrow their way into the heart of the plant. Severely infected Century Plants look wrinkled or shriveled and emit a foul odor. The rotting plant tissue eventually collapses and the plant dies. Controlling Agave snout weevil is difficult, but spraying the base of the plant with a broad-spectrum insecticide in the spring often helps prevent infestations from occurring.
Recommendations Avoid Century Plant problems by providing your plant with the best possible growing conditions. These succulents perform best when planted in fully sunny areas, although they can handle some light shade. Century Plant grows best in sandy or gritty soils with dry to medium moisture. These drought-tolerant plants only need occasional watering in dry summer weather to remain healthy. Give the plant plenty of room to grow and make sure it is planted away from foot traffic. The sharp spines can poke you and cause your skin to swell painfully.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Cacti are easy-care houseplants because their feeding and watering needs are extremely low. You can largely ignore them and they still thrive. But if you’re a chronic overwaterer, cacti may be a source of endless frustration. When your cactus has clearly been overwatered, don’t fear — there is a chance you can save it. If there is no fungal or bacterial rot present, a change of neighborhoods may be enough to get your cactus back on track.
Damage Assessment If you suspect overwatering and damage, such as soft brown spots, are obvious on the outside of the cactus, unpot the plant by wrapping a few layers of newspaper around it and tipping the cactus out. Carefully brush the soil from the roots and check them for brown or black areas. Extensive damage may be difficult to fix, but if most of the roots are still white, you’re in good shape. Cut away the black and brown roots and leave the cactus out of its pot to dry. If brown or black rot areas are extensive, you will need to reroot the cactus. A cactus that has only been occasionally overwatered will recover without further drama.
Encourage Drainage When overwatering is a chronic problem, help the cactus to shed as much water as quickly as possible in the future. Select an unglazed clay pot only slightly bigger than the cactus and fill it with a commercial cactus mix. Pot the cactus in the mix gently, so you don’t upset its delicate roots. The clay pot will wick away more water from the root zone while the loose cactus mix allows water to drain quickly and completely. You should only plant very large landscape cacti directly in the ground because landscape plantings give you less control over drainage.
Rerooting When roots or tissues are extensively damaged from overwatering, use a sharp, clean knife to cut away all the rot from the cactus. Even a small portion of healthy tissue can regenerate a whole plant, but if you leave the rot behind, it may continue to spread. Allow the cactus to dry on the counter for several days until a thick scab forms on the cut sections. Place the remaining cactus section into a clay pot with cactus soil and bury it about 1 inch (2.5 cm) deep unless there isn’t much of the cactus left — in that case, bury it about halfway. Don’t water the cactus for the first week, and only water sparingly after that until new growth appears.
Proper Watering Once your cactus is repotted and ready for success, correct watering is vital to prevent new problems. Only water cacti when the top 1 to 2 inches (2.5 to 5 cm) of the soil — depending on the size of the cactus — is completely dry. Do not water the plant from the bottom and never leave it sitting in a saucer of water. It is much better for cacti to be dry than to be wet — a good rule of thumb is to water about once every 10 days.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Succulents are hardy plants that add a striking appearance to any garden or home. Performing best in U.S. Department of Agriculture hardiness zones 3 through 9, succulents are good plants for the novice and expert gardener alike, as they require little attention. Because succulents are desert plants, they should be watered sparingly. Succulents are typically not susceptible to insect or pest infestation, but overwatering can lead to root or stem rot, a preventable and easily fixable disease. Succulents with signs of root or stem rot should be treated immediately.
1. Check the plant for infected areas. These typically appear as dark brown to black spots or areas on the low part of the plant. Other signs of root or stem rot include puckered flesh with a dark tint around the infected area. 2. Stop watering a plant with rot. Remove the plant from its pot. Remove the soil mixture and clean out the pot thoroughly to ensure no remnants of the fungus are left.
3. Cut the infected black stem from the plant with a garden knife. Let the healthy portion of the plant dry naturally for several hours, keeping the succulent out of direct sunlight during this process. If other areas of the plant are showing minimal signs of rot, keep an eye on the plant. Succulents can recover from stem rot if properly watered and placed in a warm, dry location. 4. Using the cleaned out pot or a fresh one, combine equal parts soil, coarse sand and peat moss. Don’t reuse any of the materials used with the infected plant.
5. Pour roughly 2 inches (5 cm) of the mixture into the pot. Place the newly doctored succulent into the pot with the roots lying on top of the soil. Fill the pot with the soil mixture until it reaches the base of the stems. Firmly pat the soil around the plant. 6. Place the succulent in a brightly lit spot with warm temperatures. Succulents prefer dry climates, so don’t place the plant in a humid location. 7. Water the plant with just enough water to moisten the soil one week after repotting. After the soil has completely dried out, you can water more thoroughly.
Succulents grow best in well-drained soils that provide a high water-holding capacity. Planting succulents in a clay pot with a drainage hole ensures there is no sitting water and that the soil dries out between waterings. Succulents are dormant during the winter and should only be watered lightly at this time.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Christmas Cactus is a hardy tropical cactus that brightens the environment with gorgeous, red and pink blooms around the winter holidays. Although Christmas Cactus is easy to get along with and requires minimal care, it is susceptible to root rot. Usually, this dreaded fungal disease is not caused by inattention, but is the result of improper watering.
Signs of Root Rot A Christmas Cactus with root rot displays wilted, limp, sagging growth, but an inspection of the roots will tell the tale. Remove the plant gently from its pot. If the cactus is affected by rot, the roots will display blackened tips. Depending on the severity of the disease, rotten Christmas Cactus roots will be slimy with black or brown decay.
If you determine that your Christmas Cactus is rotting, it’s critical to act fast. Rot is a deadly disease and once it progresses, the only option is to discard the plant and start fresh. If part of the plant is healthy, you can use a leaf to propagate a new plant. Treatment If you catch the disease early, you may be able to save it. Remove the Christmas Cactus from the container immediately. Trim away affected roots and rinse the remaining roots gently to remove fungus. Place the plant on a paper towel and put it in a warm, well-ventilated location so the roots can dry overnight.
Place the Christmas Cactus in a dry pot with fresh, lightweight potting soil the next day. Be sure the pot has a drainage hole so the soil can drain freely. Wait a couple of days before watering the newly potted Christmas Cactus. Prevention When you resume watering, be sure you understand the most effective way to irrigate your Christmas Cactus. Always water thoroughly until water drips through the drainage hole, then let the plant drain before returning the pot to its drainage saucer. Never let the plant stand in water.
Be careful not to kill the plant with kindness; slightly underwatered conditions are healthiest. Don’t water until the top 0.5 inch (1.2 cm) of soil feels dry. Water sparingly during the winter months, but don’t allow the potting mix to become bone dry. Place the plant in bright sunlight during fall and winter and in light shade during spring and summer.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Cacti are remarkably durable and low in maintenance. The succulents need little more than sun, well drained soil and rare moisture. The pests and problems common to the plant group are minimal and usually easy to surmount. Cactus problems may range from sucking pests, like whitefly, to common rots from bacteria or fungal disease. One of the telltale signs of a problem is a soft, mushy cactus.
The arid gardener may ask, “Why is my cactus going soft?” Likely causes are disease, cultivation and improper site and ambient conditions. Cacti generally have low moisture needs. They thrive in temperatures above 70 to 75 °F (21 to 24 °C) in sunny locations and require little supplemental nutrients. Potted plants need good drainage holes and a soil mix with plenty of grit. In-ground plants have similar requirements.
As with any plant, cacti can become diseased or damaged. A common problem is soft spots in the flesh of the plant. These may be discolored or corky around the spot and the center is mushy and wet. The reasons for such spots may be disease or simply mechanical injury to the pads and stems of the cacti. Cactus rot issues must be dealt with quickly to prevent spread to the rest of the plant and serious loss of vigor, which may become permanent. Problems with Fungal and Bacterial Diseases Bacteria and fungus are introduced to the plant from openings in the flesh. The open areas may be from insect or animal activity, damage from inanimate objects or heavy weather, such as hail. The action of injury isn’t important, but the damage from fungal spores or bacteria is crucial. Warm, moist conditions accelerate the production of fungi spores and increase bacterial production. Once the organism takes hold in your plant, you will see soft, mushy cactus. Symptoms to watch for include small sunken spots, discolored scabs, round soft areas surrounded by fruiting bodies, and black or other colored dots on the surface of the cacti skin. You may even notice some oozing of your cactus plants.
Treating Cactus problems that have gotten into the root usually result in a slowly dying plant, while topical issues in the upper body can be treated easily. Most cacti respond well to excising the diseased tissue. Use a sharp sterile knife to dig out the damaged flesh and allow the hole to dry out. Don’t water overhead as the wound closes. If the damage has infected the roots, there is very little you can do. You can try to repot the plant, removing diseased soil and replacing it with sterile soil. You should wash the roots off well before replanting in fresh potting medium.
A soft, mushy cactus can also be saved by taking cuttings and letting them root for a fresh new plant. Allow the cutting to callus over for a few days before you insert it into sand. Rooting the cutting may take several weeks. This method of propagation will produce a healthy cactus that is the same as the parent plant.
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Dummer. ゛☀
2017年09月19日
Dummer. ゛☀
Crassula ovata also known as Jade Plant is a succulent often used as a houseplant. This well-behaved plant blends into the landscape in USDA hardiness zones 9 through 11, where it thrives on neglect. Few pests or diseases affect Jade Plant, but when white powdery mold appears on its leaves, it is often the result of environmental problems. If you have white mold on your Jade Plant, you’re more likely dealing with powdery mildew. True to their easy-care nature, though, Jade Plants bounce back from powdery mildew once it is properly treated.
Powdery Mildew Powdery mildew is caused by several different fungi that grow in a thin layer on plant tissues. In perennial plants such as Jade Plant, the fungal bodies can overwinter in buds, re-emerging when conditions are ideal for their growth. Spores are often distributed by the wind to new, uninfected plants or spread in greenhouses from plant to plant. Temperatures between 60 and 80 degrees Fahrenheit (16 and 27 degrees Celsius) are required for germination, along with a relative humidity above 90 percent. Standing water on leaves is not necessary and can actually inhibit spore germination in some cases. Standing water encourages other fungal growth, through, so it should be discouraged.
Damage Powdery mildew begins as a white powdery coating on the plant’s leaf surfaces, but soon spreads, penetrating plant tissues and sending out spores. Emerging vegetation may be dwarfed or distorted and covered in white mildew. Jade Plants also develop corky brown lesions where powdery mildew is taking hold. If not addressed, this mildew will spread farther, resulting in leaf drop and the eventual death of the Jade Plant.
Cultural Control Cultural control is effective for powdery mildew. Plant Jade Plants in full sun and trim them to encourage better air circulation. Reduce watering if the plant’s soil is often moist; always allow the soil to dry before watering Jade Plants. Powdery mildew spores can be killed with water, but be careful to wet the plant early in the day so that it can dry completely. Stop misting house Jade Plants, instead water them at the base of the plant since humidity around the plant is what encourages the growth of powdery mildew.
Chemical Control Several chemicals are available for chronically infested plants or those that are victims of environmental conditions beyond the control of the gardener. Test a safer pesticide such as horticultural or neem oil on a small spot on your Jade Plant before spraying the entire plant thoroughly. If an outside Jade Plant yellows or shows signs of sunburn, utilize a sunshade until signs of powdery mildew are gone to prevent serious damage. Never apply horticultural oils when temperatures are above 90 degrees Fahrenheit (32 degrees Celsius).
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