problem solver

Cochineal scale

IDENTIFICATION — Cochineal scale are small (up to 1/4-in.) crimson insects that attack Opuntia, such as prickly pear and cholla cactus. They’re easy to spot by the little tufts of white cotton that they produce to protect themselves from the sun, predator insects and birds.

DAMAGE — The insects suck the juices of the cactus and are found mostly in the lower elevations in the western United States and Mexico. The legless females can’t crawl — but the juvenile insects travel by hitching rides on the feet of birds. If left unchecked, cochineal scale can kill the plant.

CONTROL — When there are just a few insects, a sharp jet of water will knock them off the pads. For heavy infestations, spray the plants with malathion three times, at weekly intervals. That ensures that you get all of the newly emerging critters. You’ll know they’re dead when the cottony covers turn dingy gray or they no longer “bleed” red when you pinch them.

problem solver

Red leaf edges

When you bring a succulent plant that was growing outside back inside in winter, it can become stressed as it gets used to a new environment. The same thing happens when it goes back outside in spring and has to change again. Many succulents, including the jade plant (Crassula ovata) shown here, react to this stress by turning red on their leaf edges and losing their green color.

Be patient, once the plant adapts to its new growing conditions, it will regain its green color. In spring, when you first take the plant back outside, put it in the shade for a couple of days, then move it gradually back out into full sun. After a week or two, the plant will acclimate to its new home and green up on its own.

problem solver

Whiteflies

IDENTIFICATION — If you brush the foliage of a plant and a white cloud floats up and quickly resettles, chances are your plant has whiteflies. Look on the undersides of the leaves and you’ll see the tiny white insects in the illustration.

DAMAGE — Larvae suck the sap from new leaves, which causes them to turn yellow and drop. Sometimes the young insects secrete sticky honeydew as they feed. The honeydew can harbor sooty mold, another symptom you may notice. It looks like black dust stuck to the leaf surface.

CONTROL — Whiteflies can’t survive cold winters, but overwinter on plants brought indoors and also on plants outside in southern zones with mild winters. Check everything you bring into your garden carefully. Also, check house plants before you bring them indoors in fall.

These tiny insects move through their life cycle so quickly that they can build up a devastating population in a matter of weeks. At each stage of life, they respond differently to controls. You can use yellow sticky traps to capture the adult whiteflies or knock the adults and larvae from the leaves with a strong stream of water. The larvae and eggs can also be rubbed from the leaves or use an insecticidal soap about once a week over several weeks to take care of them.

poinsettia care

The classic red poinsettia is ever-present come December, and you can buy it as easily in the supermarket as the floral shop. Many shades of red are available, not to mention pink, creamy white, yellow, variegated and bi-colored.

Poinsettias are simple to care for. Put them in a bright window (but not in direct sun) and water the plants thoroughly when the soil surface is dry to the touch. (Discard any water that collects in the saucers because poinsettias don’t like wet feet.) The best temperature for poinsettias is between 60 and 70 degrees. Try to keep them away from hot, dry air or cold drafts.

The coloring often lasts until spring, but you can bring them back for an encore. When blooms fade (around May), cut the plants back to about 5 in. and set them in the garden for the summer. Water sparingly until new growth starts, then when needed. Add a water-soluble fertilizer every three weeks. To get your poinsettia to bloom in time for Christmas, keep the plant in total darkness for 14 hours a night from September to late November. One idea is to cover the plant with a cardboard box as soon as you get home from work and then uncover it when you leave the house the next morning.

problem solver

Too much fertilizer

There is such a thing as too much of a good thing — fertilizer, for example. In house plants, such as the dracena in the photo, too much fertilizer can cause the leaf tips to turn yellow and eventually brown. The soil surface or pot rim may develop white or gray deposits that look like salt.

If you suspect your plant has received too much fertilizer, the best thing you can do is run clean water through the pot several times. Let the water run through the soil and out into your sink or use a hose outside.

If the water drains slowly, switch the plant to a container with better drainage. While you’re at it, use new potting mix when you repot to give your plant a fresh start. You won’t be able to reverse the leaf damage that’s already been done, but you can keep it from happening to new growth. Dilute your fertilizer mix to half the concentration you’ve been using to prevent this from happening again.

problem solver

Ficus leaf drop

If you’ve grown a ficus, you probably know that it can be a little finicky about where it calls home; the leaves will turn yellow and drop off for no apparent reason. It does this because something in the environment has changed. Perhaps you moved it recently and now it’s not getting enough light, or it’s getting too much, or it’s sitting under an air vent and drying out.

Losing its leaves won’t necessarily kill your ficus, though. Many times, the plant will put out new leaves and will be fine. Click on the photo to see what the new growth looks like.

Whatever the cause, house plants need a consistent environment. If you need to relocate one, do it in smaller steps over a period of time. Move the plant to its final home for a few hours each day. Instead of a quick change that shocks the plant and causes dramatic reactions — like dropping all its leaves — a gradual move will allow it to adapt to its new environment.

A buildup of dust and grime makes it hard for your house plants to absorb the light they need to stay healthy. Here are a couple of ways to easily and gently clean the leaves of your favorite indoor plants.

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Anxious for spring? We’ll show you a colorful and stunning indoor spring combo and how you can put it together in a snap.

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overwatering
house plants

Overwatering house plants is just as bad as underwatering them. How do you tell if your plants are overwatered? Start by checking the soil. If the soil feels wet to the touch and you haven’t recently watered it, it may have been overwatered. Smell the soil too. A fermenting or rotting smell might indicate that the roots are decomposing. Examine the roots. Healthy roots will be white or light yellow in color and firm. Damaged, rotting roots will be brown or black and soft.

The top of the plant might not look like it has too much water – in fact, it might be wilted. Wilted foliage is often a sign of too little water, but it can be a sign of too much as well. An overwatered plant that is wilted doesn’t have any living roots. Leaf tips or margins may also turn brown if the plant has been overwatered.

After checking the plant’s roots, you can decide what action needs to be taken. If the roots are reasonably healthy, then you need to allow the roots to dry out before you water again. Don’t allow the soil to dry so much that the plant then wilts. If the roots have begun to rot, then it is best to start over with a new plant. To ensure proper watering in the future, water only when the plant needs more water. Check soil moisture by touching it, using a moisture meter or by checking the weight of the pot. Never leave your plants sitting in water.