Doesn’t it happen so suddenly? One week temperatures are in the 80’s with nights still mild, and then one morning you wake up to find that the overnight temperatures dropped below 50F. If your tropical houseplants have spent the summer outdoors, this is your cue to start bringing them indoors.
First: Groom and Assess for Pests
Your Peperomia, Ferns and Snakeplants have probably put on nice growth over the summer, benefitting from the good air flow and more humidity. Now, as the days become both cooler and shorter, your houseplants may be begin to let go their oldest leaves. Groom and assess for pests. Pest problems that are minor outdoors become a bigger deal inside.
I find that there are often a few slugs or snails hanging out under the pots. Remove them. We began using a food grade diatomaceous earth to deter slugs on our container plants and recommend it. The teensy particles are sharp enough to inflict cuts on their bodies. It is advisable to wear a mask so as not to inhale the small particles when applying. Dust the soil and even the foliage if you notice that your leaves have been munched on. The diatomaceous earth also seems to deter other pests.
Be on the lookout for aphids on fresh new growth, whitefly on the leaf undersides and mealybugs in leaf/stem crevices. Sometimes a forceful spray with the hose can take care of things, but I recommend a follow up using a safe organic pesticide like Insecticidal Soap for aphids or a Neem Oil product which can control not only aphids but whitefly, some mites, caterpillars and scale. Use rubbing alcohol on a Q-tip to swab and kill mealybugs. (Inspecting regularly and catching the first signs of activity is the best defense; if you discover a plant has a bad mealy problem it is best to just ditch that plant). Be sure to follow the instructions on the product label, and repeat at the recommended intervals as a preventative for any new hatching. Do isolate any problem plants.
Hold back on the fertilizer
All plants will slow down in growth, so you may want to wait to repot any oversized plants until spring. Slow down on fertilizing unless you have a plant that is a heavy fall or winter feeder.
Most succulents can take cooler nights than the tropicals, but don’t let them get bitten by a frost. For more info on succulent wintering over I’ve written more extensively on this topic at this blog post link.