Organic Gardening: Winter houseplant care
With so many cold months every year, Michigan is a great state for house plants. And having a few green things around can help you remember what the color green looks like as you contemplate the frozen landscape out your window. Keeping your plant friends healthy shouldn’t take much, but there are a few important points to keep in mind.
First of all, don’t overwater. Tropical and succulent houseplants grow much less in winter and need less water as well. Tropical plants may only need to be watered a few times a week and succulents perhaps once a month. Water your succulent plants completely and then let them dry out for several weeks. Other plants should be watered only when the soil has dried out about an inch or so beneath the surface. Pay special attention to plants near radiators and heating sources. Although plants aren’t using much water, the combination of heat and winter air can dry them out quickly.
Try to place your plants as close to windows as possible, without letting the leaves touch the glass. Some houseplants like snake plant (sansevieria) or peace lily (spathiphyllum) seem to do well away from direct sunlight, but most prefer to get as much light as possible. This is a balancing act, though, because the cold air from windows can damage or kill plants. On the very coldest nights, move plants off of window ledges to protect them. During really cold periods you might have to keep them away from windows for a few days.
Your plants will also appreciate as much humidity as you can give them. Placing pebbles in their trays with water can be good as long as the pots themselves aren’t submerged. I’ve noticed that air-plants and orchids seem to appreciate the humidity in bathrooms and I try to place them next to a bathroom window if possible.
Dusting plants periodically can also be a good idea. This keeps the dust from blocking light absorption.
Other periodic care will involve removing dead leaves and dead branches on some plants. Tropical plants especially will grow a lot during the summer, but might not be able to support all that growth over the winter. Dropping a few leaves isn’t necessarily a bad sign, it might just mean the plant is adjusting to its new circumstances.
Hold off on fertilizing for most of the winter. Come February, plants may begin to respond to the increased day length even if it is still bitterly cold outside. A top-dressing of worm castings–which can be purchased as well as produced in a home worm bin–can provide a good organic, slow-release fertilizer.
The end of winter can also be a good time to evaluate plants to see if they need repotting. If roots are peeking through the drainage holes in the bottom or if you can lift the coiled mass of roots out of the pot altogether, you need to repot. It’s good to disentangle these roots so they don’t keep circling. I’ve sometimes just cut off the bottom inch or so with a wood-saw to little negative effect.
Move the plant up into a larger container, but not too large. The rule of thumb is that the new pot should be about 2 inches bigger in diameter than the old one. All containers should have drainage holes in the bottom to prevent water-logging and disease. Water thoroughly to help the soil and roots settle and to make sure the potting medium is fully absorbing the water. You might fill the kitchen sink with water and place plants in there for 10 or 20 minutes after repotting.
All in all, houseplants generally take care of themselves during their winter slumber, so long as you do some of the things listed above to keep them from becoming overly stressed. It’s helpful to remember that these plants were chosen for their ability to tolerate neglect and that they have likely survived owners far worse than yourself.
Brian Allnutt is a freelance writer and organic gardener in Metro Detroit. You can reach him at firstname.lastname@example.org.