Each summer my indoor geraniums and begonias take a vacation outdoors for a few months. There they thrive in filtered light and bloom all summer. However, each fall I have to abruptly end that vacation to save them from the cold. Before I bring the plants back in, I check them over thoroughly to get rid of pests.
My friend Roni recently asked me what to do to her geraniums to rid them of pests before she brought them back indoors. She had some good tactics in mind to reduce summer hitchhikers. She planned to remove the old soil and replace it with fresh potting mix to eliminate soil-borne insects. She was also going to scrub the pots and saucers down to eliminate any additional stragglers. If you also have plants to bring indoors or that you have recently brought in from an outdoor sojourn, there is an alternative to repotting. Soak the entire plant, leaves, soil and all, for 15 or 20 minutes in a tub of lukewarm water to drive the critters out of the soil and off the plant. Remove and discard any pests you find. Don’t use this semi-drowning technique on cacti and succulents though.
Hosing the plants down with plain water can knock off quite a few pests. To be effective, leaves have to be sprayed on top, underneath and where they join stems. Spraying all the plant surfaces with insecticidal soap is another option. Insecticidal soaps work well against soft-bodied insects. You may want to repeat the treatment after 7 to 10 days as new generations hatch. While there are more toxic insecticides than insecticidal soap available for use on houseplants, I don’t suggest using them when there are pets in the house that might nibble or eat leaves or flowers and ingest the pesticide.
Remove any damaged or dead foliage or flowers and prune the plant to tidy it before bringing it back inside. Isolate the returning vacationer away from non-vacationed plants for about six weeks to prevent the spread of any potential hitchhikers that you may have missed. I have found that plants may look quite clean when first brought in, but are often covered with aphids and honeydew within a few days or weeks, when the darn critters hatch from unnoticed eggs.
With good light, a little fertilizer and proper watering, your houseplants may bloom through the winter.