Garden Help Desk: If you’re cold, they’re cold — Bring your houseplants back in
If you had some of your houseplants out in the landscape for the summer, you’ve probably already brought them back inside. But if you’re still keeping a few hardier indoor plants outside in a sheltered spot, now is the time to get them indoors. Even though your houseplants need to be in where they’re protected from frosty winter temperatures, not everything about the great indoors is ideal for them, though.
Houseplants can do well when they’re given a shaded outdoor place for the summer. They’re exposed to many pests, but there are many natural controls outdoors that help to manage the situation. The problems come once plants are brought back indoors — pests can travel back inside on your plants, away from the natural controls outdoors. Your plants are already back inside now, but you should still check them carefully for mites, aphids and other common pests. Look on the undersides of leaves and along stems. Pay special attention to leaf and flower buds and examine leaf axils (the places where leaves attach to stems).
Many hitchhiking pests can be washed off your plants with a strong spray of water before you bring them. The shower or kitchen sink will work too, if you find pests now that your plants are indoors again.
The pests that persist after you’ve given your plants a strong rinse can be controlled by applying insecticidal soap or horticultural oil. Test these products first on just a leaf or two of your plant and wait a few days before treating the rest of the plant to make sure your particular houseplant can tolerate the treatment. Another option is using a systemic insecticide. It’s best applied a few weeks before you bring your plants indoors but can be used later, if needed. Systemic insecticides aren’t always effective for mites but can give good control for aphids, scale and mealy bug.
Moving back indoors requires your plants to make some adjustments.
The humidity in your house may be lower than your plants were accustomed to outside. Check soil moisture a little more frequently to make sure they aren’t drought stressed while getting acclimated to being indoors, but don’t overwater, either.
Setting your plants in the right place will make their adjustment easier. Don’t place your plants near any heat vents, fireplaces or wood stoves and avoid drafty locations near exterior doors and windows.
It won’t take long for your plants to adjust to being back indoors, but you’ll want to inspect them frequently for the first few weeks to make sure there aren’t any problems you can nip in the bud.
Preparing trees for winter
Here are some do’s, don’ts and depends to keep in mind while you do your winter prep for trees and shrubs.
Don’t prune. Save your routine pruning for spring and early summer. Pruning once midsummer has passed can stimulate new growth that won’t be winter hardy. Avoid pruning unless you’re removing dead or diseased branches.
Don’t fertilize. Fertilizer stimulates new growth, and you want your tree to rest over the winter.
Do use tree wrap — white or light-colored and breathable — on the trunks of trees. This is especially important for any tree that is young or has thin or dark-colored bark. This will help protect your tree from Southwest winter injury, the bark injury that happens when direct winter sun warms the bark enough for cells to break dormancy during the day and then freeze at night, killing the cells. Over time, this causes dead, peeling and cracked bark. Put the tree wrap on at the beginning of November and remove it at the start of March.
Do give all your evergreen trees and shrubs a last deep soak in late November. This will help the trees and soil enter the winter well-hydrated and reduce the chances of winter damage on leaves and needles. Don’t forget to disconnect your hose from your house spigot when you’re done!
Do apply a layer of mulch over exposed soil under your trees to insulate the soil and reduce evaporation.
Clean up the fallen leaves or leave them under the tree? It depends. If the tree is in the lawn, the leaves should be cleaned up either by raking or by mowing with a bagging or mulching mower. If the leaves are collecting on bare ground under your trees, and there weren’t any leaf diseases this year, you can leave them as biodegradable mulch and habitat for micro and macro-organisms in and on the soil.