动态第706页 - 绿手指 - 养花技巧、花生病了怎么办、花园打理和设计

2017年09月19日

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.[图片]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.[图片]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.[图片]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.[图片]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.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

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.[图片]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.[图片]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.[图片]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.[图片]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.

...显示更多

1

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

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.[图片]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.[图片]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.[图片]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.[图片]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.

...显示更多

0

2

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

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.[图片]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.[图片]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.[图片]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.[图片]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.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

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. [图片]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. [图片]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. [图片]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. [图片]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).

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

If you’re growing a Desert Rose (Adenium obesum), you probably know that it has an odd look, with a thick, succulent stem called a caudex that can become a bit grotesque as it enlarges. But its name comes from its desert-like native habitat and its colorful, showy flowers that resemble small roses. Usually easy to grow when given the right conditions, leaves on a Desert Rose might turn yellow and start to fall. This can stem from normal changes as it cycles through the year, or it might signal a problem that needs to be addressed.[图片]A Natural Cycle A Desert Rose is sensitive to frost but can grow outdoors year-round in USDA hardiness zones 10a through 12. In colder regions, it also does well as a potted plant, either kept indoors as a year-round houseplant or grown outdoors in summer and overwintered indoors. Whether an outdoor plant in a warm-winter area or a houseplant, Desert Rose usually continues to grow throughout the year, so its leaves should stay green if it’s healthy and problem-free. But in cooler areas where night-time temperatures fall between 39 and 46 degrees Fahrenheit (4 and 8 degrees Celsius) and become 60 to 64 degrees Fahrenheit (15.5 to 18 degrees Celsius) during the day, a Desert Rose behaves like a deciduous plant, with its leaves gradually turning yellow and dropping. You can prevent a potted plant from losing leaves by moving it indoors before the air cools in the fall. If you grow the plant outdoors year-round and it becomes dormant in fall, it should put out new growth as soon as the air warms in the spring.[图片]Possible Pests A Desert Rose might attract one of several pests that can affect its leaves, causing them to yellow and eventually dry up. These include mealybugs, fluffy white insects that feed on the foliage. If you see these insects, destroy each one by touching it with a cotton swab dipped in rubbing alcohol. Other possible pests include aphids — small greenish insects — and spider mites, which aren’t readily visible but make web-like coverings on leaves and buds. Both pests feed on plant juices and can cause leaves to yellow, wilt and fall off the plant. For a mild problem, use a strong jet of water to dislodge the pests. If the infestation is severe, spray the plant with insecticidal soap, diluted at a rate of 5 tablespoons per gallon of water. Repeat the spray every two weeks as needed.[图片]Fungal Problems If a Desert Rose is grown in overly wet conditions, it might develop fungal stem rot, which usually starts at a stem tip and could also affect leaves on that stem, causing them to turn yellow, then brown. Eventually, the stem darkens or turns yellow and becomes soft, with the problem moving down the stem toward the soil. To save the plant, prune the affected part of the stem back, making the cut behind the soft area and into healthy, firm tissue. Disinfect the knife or shears by wiping the blade with rubbing alcohol between each cut to prevent spreading disease.[图片]

...显示更多

1

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

Cacti and succulents have to be resilient to survive in some of the hottest and driest places on earth. Little gets past their sharp spines and tough skin, except two tiny insects that can do a lot of damage.[图片]Mealybugs and scale are particularly attracted to cacti and succulents. They can injure and even kill them by feeding on their juice. Mealybugs attack all parts of a plant, above and below ground, but are usually found on leaves and stems. A plant will be covered with what looks like sticky white cotton, and up close, you can see small, white oval bugs. Mealybugs can be tough to completely eradicate. Scale insects cover themselves with hard oval, tan or brown shells. They congregate on leaves and stems, and multiply quickly.[图片]Treat Cacti and Succulents for Mealybugs and Scale Wear gloves before handling cactus, or use bunched-up newspaper or paper towels to hold the plant. Spray water hard enough to dislodge the insects, but not so hard as to damage the plant. Nick scale off with a fingernail or tweezers.[图片]Spray the plant with insecticidal soap, neem oil or horticultural oil. Follow directions on the package, as improper use can damage the plant. Wipe mealybugs or scale with a cotton swab dipped in a solution of 50 percent rubbing alcohol and 50 percent water. Large infestations may need treatment with a systemic insecticide. This is a last resort. Avoid insecticides containing imidacloprid, which can harm pollinators. Consider whether to remove and replace the plant instead.

...显示更多

1

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

They live in the kitchen, crawling around and breeding on food, and then fly into hard-to-swat, in-your-face swarms when disturbed. If that behavior isn't a category winner, I don't want to see the competition![图片]Fruit fly (Drosophila melanogaster) invasions usually coincide with the ripening of summer fruit. Nothing draws a crowd of fruit flies like a bowl of peaches or tomatoes. So where exactly did they come from? Although it's tempting to think of these pests as alien invaders that hitchhiked from a distant land, it turns out they're natives. They usually live outdoors, though, and only come inside when they detect a potential breeding ground.[图片]Fruit fly adults only live for a few days, so their need to breed is intense. Females lay up to 500 eggs on any fermenting food source, and that includes everything from ripe bananas to garbage disposal slime. Yuck! The presence of fruit flies is often the first tip that you've got a forgotten potato in the cupboard or that your toddler spilled apple juice under the table.[图片]Despite the annoyance factor, fruit flies perform an important public service. Their larvae consume decaying matter that might otherwise turn into a source of fungal or bacterial infection or attract even more obnoxious pests, such as mice or rats. Females lay their eggs just under the surface of decaying fruit and other foods. After hatching, the grubs spend three or four days eating before they mature into breeding adults, and the cycle begins again. Their whole life cycle occurs in about eight days.[图片]Controls and prevention Getting fruit flies out of the kitchen takes a bit of persistence, but it isn't difficult and doesn't require any pesticides. Eliminate or contain their food sources by refrigerating or covering ripening fruit, especially bananas, peaches and tomatoes. Cover your kitchen compost, using a container with a fitted lid. Search the cupboard for potatoes and onions that are starting to get soft and spoil. Mop up spills under the refrigerator[图片]Rinse discarded and recyclable bottles and cans, especially beer and juice containers. Keep the garbage disposal clean.

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

Despite its name, the pickleworm’s favorite meal is squash, both winter and summer types. These pinkish or green caterpillars feed on the blossoms, stems, and developing fruits of squash, cucumbers, cantaloupe and some pumpkins.[图片]Pickleworms overwinter in tropical zones and as adult moths they migrate northward in early summer to lay their eggs on susceptible plants. Pickleworm larvae feed on flowers and tunnel into young fruits before pupating. With two to four generations per year, pickleworms are year-round pests in the southernmost part of the U.S. They can migrate as far north as the Carolinas during the summer.[图片]Prevention and Control Plant as early as possible so crops are harvested before late summer, when damage is usually greatest. In southern areas of Florida and Texas, pull up and destroy vines and leftover fruits after harvest, along with nearby weeds, to minimize opportunities for the pest to overwinter.[图片]

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px

Dummer. ゛☀

2017年09月19日

Large, ragged holes in the leaves of cabbage, broccoli, Brussels sprouts, collards, kale, or cauliflower plants are a sign that cabbageworms may have invaded your garden. The green caterpillars may also bore into the heads of these crops, leaving behind their dark green frass (droppings). Cabbage loopers cause similar damage. Plants can tolerate a moderate amount of damage without reduction in yield.[图片]The cabbageworm is the larval form of a small white butterfly (Pieris rapae) that has three to four black spots on its wings. The butterfly lays white eggs on the underside of leaves; eggs hatch within a week and the larvae feed for approximately two weeks. The larvae pupate in silken cocoons attached to the lower leaves. There are several generations per year, and they are found throughout North America.[图片]Prevention and control Cover susceptible crops with garden fabric in early spring as a barrier to the egg-laying moths. If plants are not covered, inspect them frequently. Crush the eggs; handpick the cabbageworms and drop them into a pail of soapy water. Encourage native beneficial insects, such as parasitic wasps, that prey on caterpillars. Remove plant debris from the garden in fall to minimize opportunities for the pest to overwinter.[图片]

...显示更多

0

文章

😀 😁 😂 😄 😆 😉 😊 😋 😎 😍 😘 🙂 😐 😏 😣 😯 😪 😫 😌 😜 😒 😔 😖 😤 😭 😱 😳 😵 😠

* 仅支持 .JPG .JPEG .PNG .GIF

* 图片尺寸不得小于300*300px