By Mary-Jane Pilgrim, Master Gardener

Note: The article was also published recently in the Peterborough Horticultural Society September 2021 newsletter. Apologies to PHS members who have already enjoyed it!
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If your houseplants are on “vacation” on the back deck this summer, then at around this time you should think about getting them ready to move back inside for the winter.

Bring your houseplants indoors before night time temperatures dip below 7 or 8 degrees (C).  Most tropicals will suffer damage at temperatures below 5 degrees, a few even below 10 degrees.

Sudden changes in temperature, light, and humidity can be traumatic to plants, resulting in yellowed leaves, dieback, wilting, and even death. To prevent shock when you bring houseplants back indoors, expose plants gradually to reduced lighting.

Before moving day, inspect plants for insects and diseases, and treat as appropriate before bringing plants back inside.  Spray them a couple of times over a 2 week period with a mild soap and water mix so that you don’t bring bugs from outdoors in with your plants.  Alternatively, soaking the pot in a tub of lukewarm soapy water for about 15 minutes will force insects out of the soil. Allow the plant and pot to dry completely afterwards.  If snails, earthworms, or other insects burrowed in the soil, you might want to repot the plants, placing a piece of wire screening over the drainage hole to keep them out next year.

Personal anecdote:  A couple of years ago, I brought a large cactus planter inside without inspections or the soaking method. The next day, we found a curious “deposit” left behind by some unknown critter on our kitchen floor and we kinda freaked out.  We set live traps in the house and were on high alert for a chipmunk or squirrel or even something huge with big teeth that could drag us out of bed by the big toe.  It was a little bit traumatic.  A day or so later, my son found a large toad in the living room and we connected the dots.  Turns out that toads leave very large deposits for their body size (Google it!) and closer inspection of the cactus planter showed an open hibernation hole. Whew!

Moral of the story? Check your plant pots for toads too!