Powdery mildew, which looks like a dusting of gray-white powder on leaves and is a particular plague of roses, hit some areas hard this year. The good news: If the “powder” hasn’t already disappeared, it soon will. The bad news: It probably will be back next spring.

Powdery mildew (Erysiphe lagerstroemia) is a fungus that thrives in spring, when there is lots of moisture and days get warm. Young, growing shoots of plants can dry up and shrivel, flower buds may drop, leaves may curl. Mature growth also takes a hit, but less so. Once summer arrives, the fungus struggles.

And while powdery mildew badly disfigures crape myrtles and roses, usually the fungus won’t kill plants; it just looks awful.

“Powdery mildew is something you see every year,” says Dr. Raul Cabrera, an associate professor and project leader in woody ornamental horticulture at Texas AgriLife Research and Extension in Dallas. “It’s just unsightly. For most folks, they want to do something.”

The best course of action, the experts agree, is prevention.

“The best weapon against the situation is to rely on plant cultivars that are tolerant or resistant,” says Dr. Cabrera. New crape myrtle cultivars, for instance, have greater resistance to powdery mildew than the common varieties that have been grown for years and invariably get powdery mildew. Roses that have earned the EarthKind designation also count disease-resistance among their attributes.

Other tricks in the homeowner’s arsenal:

Location — Plant ornamental plants where they will get good air circulation.

Plant roses in full sun.

In fall, remove affected leaves, to avoid spread of the fungus.

Don’t overfertilize.

Prune lightly, thinning out branches and removing broken or rubbing branches to promote good air movement.

If you can’t stand the sight of powdery mildew in spring, get on a regular program of spraying fungicides, natural or chemical.

Dr. Kevin Ong, assistant professor and AgriLife urban plant pathologist, says there are a number of fungicides to control powdery mildew.

Many chemical fungicides can be sprayed on plants to keep it in check. Organic remedies include Neem oil extract and potassium bicarbonate, a cousin of baking soda. You can even make your own potassium bicarbonate spray by mixing it at a rate of 4 teaspoons per gallon of water.

But don’t spray it or other fungicides on plants during the hot part of the day, Ong warns, as this could burn the leaves.

Even though the fungus abates in hot weather, the pathogen is still hanging around, waiting for better environmental conditions. So put control of powdery mildew on your to-do list — for spring.