MASTER GARDENERS: Follow these tips to bring houseplants indoors for the winter
The typical season for gardening in northern Minnesota ranges from May to September. In September, our weather starts getting cooler, and if you sent your houseplants outdoors for a summer vacation, now's the time to think about settling them indoors before winter sets in.
Keep an eye on the weather as it is unpredictable up here. To be on the safe side, get your plants indoors before nighttime temperatures dip below 50 degrees. Most houseplants are tropical plants and will not tolerate the cold. To reduce shock, try to bring plants in before you start running your furnace. Spend about two weeks acclimating plants to the lower light and humidity levels indoors. First, move them to a shady spot outside, then start bringing them in just at night. Eventually put them in the brightest window indoors for a while before moving them to their winter homes.
One of the most common issues houseplants have when coming back indoors is bringing unwanted pests with them. Check houseplants thoroughly for insects such as aphids, mealybugs and spider mites and remove them. Wash the leaves (tops and bottoms) with a mild soap solution or a blast of water from the hose to get rid of these pests. Submerge the pots in a tub of water for 30 minutes or so, to force out any creepy crawlers that might have burrowed into the soil. While you've got the soap and water out, scrub the outsides of pots and drainage trays, too. Keep a close eye on your plants and keep them away from other indoor plants until you're sure they're pest free.
If your plants sprawled out of control over the summer, now is the time to give them a pruning; up to a third of the plant can be pruned. Clean your pruning shears between plants with mild bleach water. Repot only if severely rootbound, otherwise wait until spring. Use a pot approximately 2 inches larger.
Reduce watering to your normal indoor schedule since your plants won't dry out as quickly as they did outside. Reduce fertilizing and stop feeding completely when plants go dormant and between the end of October and the end of February. Resume fertilizing when they start growing again in the spring.
Don't be surprised if your plants drop a few leaves as they adjust to less light, and their growth slows or stops over the winter. Keep plants away from temperature fluctuations such as direct cold drafts and hot air vents. Some houseplants can make pets sick so be aware of keeping pets and plants separated.
Like the home gardener needing a rest after a busy summer growing season, the plants you bring in will rest well if cared for using these tips.
The University of Minnesota Extension website has been updated to make finding information like this much easier. Simply type your subject in the search box when you open the Extension page—www.extension.umn.edu. For broader information go to "Learn About," and click on "Yard and Garden."
You can call (218) 444-7916 to reach the local Master Gardener voicemail to get help with your gardening problems.