Looking After Houseplants in Winter
Winter is the season when we get the most worried messages about houseplants. Leaves yellow, growth stops, and plants that looked wonderful in August suddenly look tired. Most of the time, nothing is wrong. The plants are responding to the season, and the main job is to adjust your care so you do not fight them.
Plants slow down, so you should too
Indoor plants feel winter mainly through light. Days are shorter, the sun is lower and weaker, and many plants respond by growing much more slowly or stopping altogether. A plant that is not growing uses far less water and no fertilizer. Most of the problems we see in winter come from carrying on with summer care for a plant that has switched into a quieter mode.
Water less, and check first
This is the big one. Most houseplants need water about half as often in winter, and some much less. Plants that store water, such as succulents and cacti, may need a drink only once a month or even less from December to February.
The safest approach is to drop any fixed watering routine for the winter and check the soil before every drink. Push a finger two inches in, or use a moisture meter for larger pots. Heating can dry the top of the soil quickly while the roots below stay damp, so check deeper than you would in summer.
If you are often away over the holidays, a self-watering pot can keep thirsty plants such as ferns and calatheas going for a week or two. For most other plants, a thorough watering before you leave is plenty in winter.
Move plants toward the light
A spot that was perfect in summer may be too dim by December. Move plants closer to windows, especially south- and west-facing ones, which can now be ideal without the risk of scorching summer sun. Clean the windows and wipe dust off large leaves; both let in more of the light that is available. Even the low-light plants that cope with dim rooms all year appreciate a move a foot or two closer to the glass in midwinter.
Watch the windowsill at night
There is a catch. Windows get cold at night, and leaves touching cold glass can be damaged. On frosty nights, pull plants back from the glass, or make sure they are not trapped between the window and a closed curtain, where the air can get surprisingly cold.
Fight the dry air
Central heating dries the air, and many tropical houseplants dislike it. The signs are brown, crispy leaf tips and edges, and on ferns, a steady shower of small dry leaflets. A Boston fern is often the first to complain.
- Keep plants away from radiators, heaters and warm air vents.
- Group plants together. Each one gives off a little moisture, and together they raise the humidity around them.
- Stand pots on trays of damp pebbles, with the base of the pot above the water.
- Move humidity lovers into a bright bathroom or kitchen for the winter.
Avoid drafts
Cold drafts from doors and badly fitting windows, and blasts of hot air from heaters, both stress plants. A sudden drop of leaves after a cold snap is often a draft problem. Find each plant a spot with a steady temperature, ideally above about 60 degrees Fahrenheit for tropical plants.
Do not feed, do not repot
Stop fertilizing from late autumn until early spring. A plant that is not growing cannot use the nutrients, and they build up in the soil where they can burn the roots. Hold off on repotting too, unless a plant is in real trouble with rot or a broken pot. Spring is the time for both.
Expect a few yellow leaves
Many plants drop a few older leaves as they adjust to lower light. As long as the plant is otherwise healthy and the soil is not staying wet, that is normal. Pull off yellow leaves once they come away easily and do not change anything else.
Holiday plants
Winter is also when many people receive plants as gifts, often flowering plants grown in warm greenhouses and then shipped in the cold. Unwrap them promptly, keep them away from drafts, and give them bright light. If you are shopping for a plant lover this year, some of the ideas in last year's gift guide still hold up well.
Spring will come
By March, as the days lengthen, you will notice new growth starting. That is the signal to increase watering gradually, start feeding again and plan any repotting. Until then, patience and a lighter hand with the watering can are the best care you can give.