by Diana Alfuth, horticulture educator for Pierce & St. Croix County UW-Extension
It may seem like summer only started yesterday, but in northern Wisconsin, the time to watch for first frost is right around the corner. Whether you gave your houseplants a summer vacation outdoors, or have some nice container plantings you’d like to enjoy indoors for a while, keep your eye on the weather and bring the plants in before they experience chilling or frost injury.
Before you bring them in, clean off any dead or dying foliage. Look under the leaves and on top of the soil for any insects, pupae or other critters that may be hunkered down in the container. Even small frogs have been known to hitchhike indoors, and go hopping across the floor! Quarantine plants for a few days. Wasps or other insects emerge in the warmth of the house, and pests such as aphids, can spread to other houseplants.
Even though you put the plants in front of bright, sunny windows, shorter days and weaker sun will cause all houseplants to slow down growth for the winter. Therefore, don’t fertilize (which may encourage spindly growth) until late February, when a plant’s activity increases, and water only when the top half-inch of soil gets dry. You can expect some leaf drop as the plants adjust to the lower light conditions. Pinch plants back when growth picks up again in late winter to encourage bushy, robust plants, ready to enjoy inside or outside next summer!