July 19, 2015

Spring in the garden, potting flowersMany people by tropical plants for the patio and when cold weather threatens, they bring them inside for winter. These usually include palms, hibiscus, ixora, mandevilla, gardenias, and many “houseplants” used for “tropical” look on the patio or deck.

The first thing to do before bringing them inside is to acclimate them for the low light conditions of our homes in Michigan in the winter. Begin well before the nights start getting cool, by moving them into less sun. When you finally bring them in before the nights consistently fall below 50 degrees, make sure you put them in as much light as you can. An important thing to do, that most people don’t even think about, is to wash the windows where the plant is going to be placed. The more light they get the more likely they will be happy.

The big risk when bringing plants in from the outside is the pests that might be hitchhiking a ride in where they can stay warm and cozy for the winter. Be proactive by spraying your plants with reasonably forceful stream of water before bringing them inside, hopefully removing bugs or eggs before they enter your home. You may want to treat the soil with a systemic insecticide as well, to double your chances of bringing in a pest free plant. Even being proactive may not keep pest from sneaking in on your plants, so being able to detect and identify the hitchhikers is key to treating the problem. I highly recommend having a magnifying glass on hand at all times when dealing with plants, especially for ‘over 40’ eyes. At the first sign of trouble, quarantine your plant from your other plants before it spreads through the whole collection

I’m going to talk about five most common houseplant pests, how to detect them, and how to get rid of them.calico scale

The first pest is the mealybug. They are extremely slow moving insects which like to hide in crevices and under leaves.

Scale is another hard insect to eradicate once you have them. Scale look like brown bumps and they are attached to your plant, sucking the life out of it. Scale does not move like mealybugs, unless they are in the crawler stage.

Mite isn’t an insect at all, but is an arachnid, like spiders and ticks. Their feeding makes for a speckled leaf as they suck the juices out of the plants. If numbers are large, webbing will appear. The speckling and webbing is probably all that you will see.

Thrips Are the next pest that may appear on our indoor plants. Thrips are very hard to see, like mites. They are quite often seen on African violets and the spilled pollen falling down on the petals of the plant is a telltale sign that you have thrips.

The last pest is the most obvious, as they fly in your face. Fungus gnats are the most easily detected, but also the most wrongly identified pest. “I have fruit flies in my plants” is the best indicator that fungus gnats have moved in. I tell people if you don’t have any rotting fruit, you don’t have fruit flies. Fungus gnats do resemble fruit flies, but live in the soil of your too moist houseplant.

How do you eradicate these plant juice sucking insects?

One way is to get some cotton swabs, dip them in alcohol, and touch each one of the insects. The alcohol removes their protective coating and dries them out. Obviously, this would be a procedure to use if you catch the problem early. Another solution, and it can be used in combination with alcohol, is neem oil. Also, you can use a product called Bonide Rose Rx, which contains neem oil and it seems to help keep them under control by smothering the insects. Insecticidal soap is another reasonably safe product that can be used.