The summer of 2019 has been unique for sure. Yet, one thing we can count on is the need to prepare our vacationing houseplants to return inside for the winter season.
For many, we take them outside to let Mother Nature nurture them back to a better state of health, knowing that once back inside, they will be in less than a perfect growing location. You may have set them out on the ground under shrubs or evergreens, put them on the edge of the patio or next to the home. Since houseplants are not cold-tolerant, the best practice is to get them acclimated to being indoors long before we have cool and frosty temperatures outdoors, and long before the home furnace is running
Look at each houseplant carefully to determine if you really want to bring it back in the home. Some have grown too big over the summer for the space inside. Seasonal plants, like the poinsettia you nursed along until it could go outside, may be good candidates for the compost pile, as getting them to re-bloom is difficult and you are likely going to get another one anyway. Weak houseplants that never bounced back all summer long are also good ones to say goodbye to.
Once you know which plants are headed back indoors, it is time to clean them up; that includes removing any dead foliage, picking out the outdoor litter that accumulates during the summer and perhaps a little trimming to make them more uniform.
The next step is very important. Inspect them for insects. They have been outside so they have been host to a variety of outdoor pets, such as sow bugs, spiders, and earwigs, to name a few. A strong stream of water to both the top and lower leaf surfaces will take care of the bigger bugs, and flushing the pot with lots of water will drive out the soil insects. If you find spider mites or scale on any of the plants, a treatment with insecticidal soap or synthetic insecticide is needed, with two or three repeated treatments to be sure the life cycle is broken. This is much easier to do while outdoors in the open than dealing with mites in the home later. (As always, read and follow label instructions.)
Almost done now. Houseplants in the full sun now should be moved to a shady spot to start the acclimation process to lower light levels. Along with that, begin to extend watering intervals. The goal should be to bring in the plants before cold weather gets here AND before the furnace kicks on. This can be done gradually, bringing in the more sensitive plants first and finishing with the hardier houseplants. Bring them in on the dry side and begin to water them carefully, as the need for water will be less as they adjust to the lower light levels. Do not be surprised to see some yellow and falling leaves as the change occurs.
Last, but not least, set a deadline to be done so you are not scrambling after dark to get them into the garage the night of the first frost!
About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.