Central air draws power even in winter

Q Is it true that my central air conditioner is still using electricity even though it's winter and my furnace is running?

A Yes. Central air conditioners have a heating element to keep the oil warm, but it's not needed unless the air conditioner is operating. The heater doesn't go off when you change the thermostat from cool to heat. You need to turn the power off at the unit, or flip the circuit breaker to the unit.

Important: You must turn on the power to the central air conditioner at least 24 hours before using the air conditioner when summer comes around.

Plant rescue Q Can I rescue a plant with spider mites and white spots on the leaves?

A Maybe. Many house-plant insect problems can be controlled with nonchemical methods, particularly if the infestation is light.

Washing: Use a soft cotton cloth dipped in a mild detergent solution ( 1/2 teaspoon per quart of lukewarm water) to wipe small numbers of aphids, mealybugs, scales or mites off plants with smooth leaves. You can also dislodge a light pest infestation with a forceful spray of lukewarm water.

Handpicking: It's easy to remove and dispose of large pests such as cutworms, caterpillars and millipedes that infest houseplants outdoors in summer. Earthworms can be driven out of the soil by setting the pot in a tub of water to saturate it. You may also remove small numbers of scale insects or mealybugs with a fingernail file or pen knife.

Sticky traps: Sticky traps are flat cards with glue on the surface. Usually colored yellow, they capture insects that land on them. While these traps can reduce the number of flying insect pests, they won't eliminate an insect problem alone. Sticky traps are most useful for detecting the presence of whiteflies, fungus gnats, winged aphids and thrips, which then alerts you to take additional action.

Pruning: An insect infestation may be confined to a few leaves or branches or may be particularly bad in those locations. Eliminating the worst branches will make it easier to control pests on remaining parts of the plant. If an infestation is truly isolated, pruning may be all the control that's needed.

Give up: When a houseplant is heavily infested and badly damaged, the best course of action is to throw the plant away. Minimize your losses and avoid exposing other plants to the same pest problem. If you are reluctant to discard the plant, prune it practically to the soil. If it resprouts, watch new growth carefully for signs of infestation.

Insecticides: If you still have an insect problem after trying nonchemical methods and want to save the plant, consider using an insecticide. They're most commonly found as aerosol or ready-to-use liquid products at nurseries, garden centers, building supply stores and discount variety stores. Selecting an insecticide can be a challenge. There is a larger selection of insecticides available for outdoor use. You can take some plants outside and treat them as you would outdoor ornamentals. Read the label to be sure the product contains the appropriate chemical for your infestation.

University of Minnesota Extension Service

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-7032, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies.