Summer vacation ended weeks ago for most of us, but our houseplants are still likely enjoying warm days outside. However, their leisurely afternoons of basking in the sun are fast approaching an end.
Bringing houseplants inside to overwinter extends their lives and gives you the enjoyment of plants year-round. Plants are constantly sensing light, water, air and other elements and need a gradual adjustment from outdoors to your windowsill. Proper transition technique can help reduce their stress, as well as prevent creepy crawlies from coming inside with them.
Your first consideration when bringing houseplants inside is when. Generally speaking, for tropical plants you want to avoid nighttime temperatures of less than 50 degrees, with other plants no less than 40 degrees.
Because plants benefit from a gradual transition, you’ll want to plan a few weeks out from when you think these cold temperatures may set in. In Kansas especially, watch out for sudden freezes. It’s better to bring your plants in for the night — insects and all — and put them out again the next day than risk damage from a sudden hard frost.
Once you’ve established the timing, begin with a transition to shade. Move your plants to a shadier part of your yard, deck or patio. This will begin to prepare the plant for the lower light conditions of your home. While in the shade, reduce water and fertilizer gradually.
Your plant will always need watering, but you’ll find it will be much less in the shade and indoors than in the heat of the summer sun.
When you’re ready to move your plant indoors, select a location. Depending on the needs of the plant, the sunniest window you have will make the out-to-in movement slightly easier. Cleaning the interior and exterior of these windows will improve light quantity.
Make sure there are no heating or cooling vents blowing on the plants.
Selecting what plant to bring in is just as important as preparing them for the move. Diseased or pest-infected plants may be better off trashed than to risk infecting your other plants.
Of the plants you do move, remove any broken or dead leaves or branches, but avoid pruning because it encourages new growth.
Look for root-bound plants that are in need of a larger pot and make sure to scrub the outside of all the pots, including the lip, for hitchhiking pests.
To avoid bringing insects into your home, spray the foliage of the plants with a jet of water — with caution for more tender plants — and soak the pots in a bucket of warm water, up to the lip, for 15 minutes. This will drown or drive out any insects hiding in the soil. Make sure to allow all the excess water to drain from the soil before bringing the plant to its new location.
Speaking of water, overwatering your houseplants is the best way to ensure they won’t make it to next summer. Push your finger into the soil when you think it needs watering. A dry finger signals it’s time to water; any dampness tells you to wait.
After four to eight weeks in your sunniest window, you may move plants to a lower light location in your home. If you have too many plants — if there’s such a thing — and only one or two sunny windows, consider staggering your pot migration.
Although you certainly can buy new plants every spring, keeping houseplants over winter saves money and improves the feel and health of your home. Plants reduce air toxins, increase oxygen and, as repeated studies show, they just make us happy.
Ariel Whitely is the horticulture agent for Shawnee County Research and Extension.