Check and treat hibiscus for spider mites when bringing the plant indoors. (Proven Winners)
The time to bring plants indoors is when the evening temperatures begin to dip to 50 degrees. By waiting longer, plants often suffer stress from the fluctuation in temperatures, or just spending the night in the cold.
Lack of humidity indoors also affects plants. When the heat goes on, the air in houses dries like the desert.
Plants often react to these indignities by dropping their leaves. In an attempt to save the plants, owners water and fertilize them. When the plants donít improve, they do it again and again, which ends up killing the plants with kindness.
When plants are under stress, itís best to keep them watered so the soil remains just moderately moist and give them time to adjust.
If the leaves of plants begin to lighten and become stippled with yellow, chances are, almost microscopic spider mites are at work. They hang out on the undersides of the leaves, and if left to their own devices, all the leaves will yellow and fall and the plant will die. Again, water and fertilizer will do no good and may even weaken the plant more.
Flashy tropical hibiscus are notorious magnets for spider mites, so if you brought one indoors, plan to treat it ASAP. The folks at Hidden Valley Hibiscus (www.hiddenvalleyhibiscus.com) recommend a complete immersion in a bathtub filled with warm (90 degrees) water for 1 Ĺhours to rid plants of spider mites. Yup, it drowns the suckers.
They use a candy thermometer to check the water temperature. It should be warm but not hot to the touch. Too hot and it will burn the plant.
Before giving the plant a bath, the pot is wrapped in a square of material and secured at the base of the trunk so the soil is not displaced.
This procedure also serves to wash away salts that may have built up in the soil as a result of using chemical fertilizers. Salt build-up in the soil burns the roots of the plants and can also damage them.
You can spray for spider mites and other insects using an organic-based neem oil product, such as Bio-Neem by Safer, or the chemical based Bayer Advanced 3 and 1 Insect, Disease and Mite Control, which is also a systemic.
Whatever pesticide you use, plan to treat plants 3 times about every 5 to 7 days apart to get rid of any new hatches. Also be sure to spray the bottoms of the leaves.
Nancy Szerlag is a master gardener and Metro Detroit freelance writer. Her column appears Fridays in Homestyle. To ask her a question go to Yardener.com and click on Ask Nancy. You can also read her previous columns at detroitnews.com/homestyle.