September 25, 2015

Many people give their indoor plants a vacation outside for the summer. The month of September looms with its first chances for light to heavy frosts, so far we have

A Japanese beetle shows the damage he can do to plants.

been lucky, but it is coming soon. Tropical and subtropical indoor plants cannot tolerate frosts and need to be back inside. Before any of the plants come back inside, you should check for unwanted hitchhikers. This list can include flying, walking and scale insects, cocoons from moths, spiders, slugs and snails. Being an exotic plant on a Michigan deck does not give the plant any immunity from local insects.

If only a cursory inspection is done, many things including insect eggs can get missed. Those things may be kept in check while they are outside by natural controls, but can be a major annoyance indoors. A quick and incomplete inspection and putting the pot into a bucket of water to float out any critters minimizes a number of problems. Your deck or patio is the perfect place to do plant tune ups before they are brought in. Get a bag of soil-less potting medium, water and some clean pots and do it right. The time spent now will be just a fraction of what it will take to conquer an insect problem that migrates onto other plants or to track down an elusive tree frog indoors.

Before beginning your inspection, water the plant thoroughly. Slide the plant out of the container and check the soil, especially at the bottom of the container. Often, there will be ants that have spent their summer vacation digging out the potting medium and carrying it away. Or there could be assorted sowbugs and pill bugs enjoying the organic matter. When a cavity has been created by the missing potting medium, small frogs can move into the space. This is the perfect opportunity to pick off some of the old soil and use the new soil to repot the plant. However, if the roots are crowded, it’s time to pot up to a bigger container. Water the newly repotted plant well and let it drain well before moving the plant indoors. If the plants are on a deck that has spaces between the boards, your drop-in insects will just squeeze between the boards and move in from the bottom.

Inspect the leaves and stems for insects or eggs especially on the bottoms of leaves. Commercially prepared insecticidal soap is a good product to use if there are spider mites or aphids. For the unseen insect eggs lurking below the foliage, you can apply a systemic insecticide drench while your plants are still outside. The insecticide will move up into the canopy of foliage just in time for hatching eggs. The juvenile insects will not be able to become established on a treated plant. If the indoor plants were put into the soil in the garden, when digging them up look carefully for and remove earthworms. Outside, earthworms are valuable, but when confined to a pot, they can cause damage as they churn around in the restricted area of the pot.


SOURCE:  MSU Extension