Barbara Pierson, head gardener at White Flower Farm, is offering some advice for gardeners in the New York Times.

Heat and drought have caused insects and diseases to thrive this summer, while stressing plants so badly that they cannot fight them off.

She suggests horticultural oil for just about everything, from blackspot to mildew, and she says it makes plants unpalatable for insects.

Pierson has some other tips as well for the mid-summer garden. Check them out.

Photo courtesy of University of Georgia Center for Urban Agriculture