Gardening: Keep your houseplants alive this winter

Winter’s gentle teaser last week is a good reminder that our gardening has moved indoors for the next few months. Here are some tips to keep plants alive and happy.

As we get into the holidays, poinsettias are going to find their way home with us and they don’t like the cold; they will drop their leaves if they get too much of it. Try to pick them up as your last stop before going home and don’t leave them sitting in your car. Once home keep them in bright indirect light and away from heat vents and cold drafts. Water them when the soil surface is dry to the touch but don’t let them stand in water afterward. The colored bracts will last well into late winter and beyond. They make a good houseplant year-round but are notoriously difficult to get to rebloom. Check out the Spokane Community College Greenhouse Program’s annual poinsettia sale going on today and tomorrow. See the side bar for details.

Most houseplants go dormant once the winter light level drops. That means they aren’t going to need as much water or fertilizer as they do the rest of the year. For plants other than succulents, water when the soil is dry up to the first joint on your index finger. Don’t let the plants stand in drainage saucers full of water. Err on the side of caution; overwatered plants that droop look just like underwatered plants when they wilt. Hold off on any fertilizer or repotting until March when the light levels start rising.

Succulents like jade plants, cactus and Christmas cactus have fleshy leaves that store water for dry times. Therefore, most succulents will need watering only about every three to four weeks during the winter. If the plant isn’t too big, the best way to water it is to set it in a sink full of water to rehydrate the root ball. Drain the plant well after you take it out of the sink.

One of the most common bug issues for houseplants this time of year is fungus gnats. These tiny insects resemble fruit flies and hover around your plants. They are trying to feed on the mold that naturally grows on the moist soil surface of a potted plant. The best way to get rid of them is to add a layer of sand or fine gravel to the soil surface so the gnats can’t get to the soil. The sand or gravel keeps the surface dry and the gnats can’t breed.

The lack of light during the winter can cause some plants to turn pale and yellow. If you can move your plants to a brighter place they will benefit from it. Many plants can handle winter sunlight so take advantage of it. However, don’t put plants right up against a window as they might freeze at night. If that won’t work, set up a 4-foot LED shop light over your plants to give them some extra light.