Diseases Strike Lilacs in Local Area Yards, Pastures
Diseases Strike Lilacs in Local Area Yards, Pastures
Along with residents across the state, local residents are noticing that the lilac bushes are suffering despite frequent and heavy rains this growing season.
According to experts, such as Jon Ball, state forester with the South Dakota Extension Service, the problems are based in a high prevalence of diseases such as leaf spot, pseudocercospora and septoria. And the diseases are flourishing in response to the intense heat, humidity and abundant rains this summer.
“We’ve received many calls and emails over the last few weeks with questions regarding lilacs, from all corners of the county. Most of the calls on producer windbreaks and some I have seen in landscaping sites,” commented Amy Sis, with the Grant County Conservation District.
As conservation technicians are out checking sites, they find the affected lilac bushes are bare with exception of some leaves at the tips. Sis also reported that some lilacs are in the midst of a fall bloom this year. A fall bloom indicates the plants are under increased stress.
An excerpt from Ball’s Tree Pest Alert indicates that citizens are concerned about the prevalence of leaf spot and defoliation on lilacs in windbreaks.
“These leaf spot diseases present as brown spots starting at the margins, progressing to blotches and eventually defoliation. Most of the lilacs affected so far have been used in windbreaks,” Ball noted.
He has examined some windbreaks in which every lilac in a row is bare except for a few leaves at the tips.
“These diseases require warm, humid conditions to flourish, and it has been wet and humid this year,” Ball explained in the alert.
Ball stressed that the leaf spot diseases are not a threat to otherwise healthy shrubs. Lilacs can withstand a year of defoliation, so control is not always necessary.
“If the lilacs were affected last year and again this year, a fungicide application of Chlorothalonil (labeled for this use) can be made just as the leaves are opening next spring to reduce the severity of the disease,” Ball advised.
