University of Illinois Extension
Bring your houseplants back in now

 

[September 30, 2021] 

One activity that seems to get “put off” until the last minute is bringing in the houseplants that have vacationed outside for the summer. It is not uncommon to find ourselves out there with a chance of frost and flashlight in hand covering up the houseplants or rushing them inside the garage for the night.

A more relaxed way to handle them is to start the transition now and think through some choices ahead of time. Some of the questions you can ask yourself are: Do I have room for all of them again? Are some “compost pile worthy” and others worth saving? Are some just too big now and would taking cuttings or propagating them a better choice? Would that leave room for others? Make your goal to get them indoors before the end of September, for sure.

Insect control

While they are outside, our houseplants can host a number of insects without any apparent damage. The wind and rain helps keep any outbreak from being a problem and natural predators or the environment in general keeps the insect populations down. But, bring those houseplants inside without cleaning them up and those same insects can be quite the problem in just a few weeks.

Spider mites may be one of the worst and hardest to be rid of if they get established. Make close inspections, looking for very fine webbing across leaves and leaf petioles. They look like tiny specks crawling across the leaf underside or in the webbing on new buds or leaves. If you manage spider mites, you will very likely manage any of the other insects found on your houseplants.

When you start early, you can make several treatments with insecticidal soap or synthetic insecticide, if needed. This is much easier to do while outdoors in the open than dealing with mites or scale insects in the home later. (Always read and follow label instructions.)

Before you bring them in, be sure to rinse the foliage off one more time. There are insects in the soil as well, but they typically do not survive once inside with our drier air and low levels of humidity. You may find them dead later on around the plants on the windowsill or shelf.
 

Moisture and temperature

Bring the plants in on the drier side to allow the plants to acclimate to the lower light and humidity, and this is preferably before the furnace kicks on for the first time. You will find your houseplants will do better after you bring them in because they really do not like to be outside in the cooler temperature at night in September anyway. One of the earliest 32-degree nights recorded was Sept. 23, so don’t delay.

Starting early can help you make good choices without being rushed, and you get to relax the night of the first frosty weather and save your flashlight batteries for a real emergency.

[SOURCES: Richard Hentschel, Horticulture Educator with University of Illinois Extension]