Even inside, winter can be a challenging season for houseplants. Here are some tips on caring for houseplants during the winter months.

Bring Them Inside

If you have had your indoor plants outdoors to take advantage of the fine weather, they need to come back in right away. Don’t delay, even night time temperatures as high as 50 degrees can stress or damage some houseplants.  Inspect carefully for disease and insect problems before bringing in.

Lighting & Location

Due to the shorter day length, plants may not thrive where they have been for the summer.  Bring plants closer to the windows to maximize the available light, or invest in full-spectrum lamps to supplement the natural lighting.

Keep in mind that low-light plants still won’t take a full south or west window.  Keep all foliage at least a couple of inches from the window pane.  Pay attention to drafts – cold drafts from poorly insulated areas or frequently opened doors, or warm drafts from heating systems both can be damaging.  Also avoid placing plants near intense heat sources such as a fireplace, wood stove or heat vents.

Cut Back on Fertilizing

Even if you keep your home on the warm side, your average daily temperature is frequently cooler in the winter.  The combination of shorter day length and lower temps dramatically slows houseplant growth, so they use less water and nutrients than during the active season.

Feed lightly, with half strength fertilizers (or supplement with little primary nutrients such as HB 101) about once a month.

Water

Water needs will vary from plant to plant; in the winter most cacti and succulents should receive little or no water at all, while very thirsty plants such as Peace Lily and Natal Mahogany should still never significantly dry out.

In general for plants indoors and outside, water thoroughly but less frequently, rather than giving lots of little drinks.  While there is really no scheduling substitute for checking your plants regularly and knowing their basic watering preferences, depending on how you heat your home, watering frequency in winter typically reduces by 50% or more.

Humidity

Low air humidity caused by heating can be quite damaging during this season.  Protect sensitive plants such as ferns and citrus by creating a humidity tray.

Take a saucer a bit larger than you would usually use as a drip tray, and put a layer of rocks in it.  Add water to this saucer to just below the top of the rock layer, and place the plant on top of the rocks.  Evaporation will increase the humidity around the plant, but its roots will be protected from over-watering.