One of Minnesota’s favorite spring flowers are blooming again in late summer, a sign of stress from the extreme swings in Minnesota’s weather over the past several years.
Lilacs around Minnesota are blooming once more due to strange, stressful weather
Though it’s a survival mechanism for future lilac plants, a second bloom will not harm them, experts said.
The Minnesota Star Tribune
September 18, 2024 at 10:25PM
Many lilacs across the Twin Cities have sprouted purple and pink flowers for a second time this year during an unseasonably warm September. The re-blooming is unusual for lilacs and can be unsettling to see, said Julie Weisenhorn, a professor and the horticulture educator at the University of Minnesota Extension.
“It’s not something we’d call ‘normal’ but it’s something we’ve been seeing now over the past few years,” she said.
When trees and plants suffer from blights or pests, or are stressed by droughts, floods or other phenomena, they sometimes produce an overabundance of seed. It’s a way they’ve evolved to ensure that, if they do succumb, their progeny has a chance to live, Weisenhorn said.
So during droughts, oak trees may produce a super-crop of acorns. And lilacs will sometimes produce a second bloom in the fall.
Minnesota is not experiencing drought right now. The summer of 2024, warm September aside, has actually been the most typical weather season the state has experienced in years.
“Sometimes it takes a little while for plants to react,” Weisenhorn said. “So you have to think back to last year and even the year before last, and realize how stressed these plants were doing those extreme dry summers, and then going through a strange winter with no snow and very little cold.”
That drought was followed by one of the wettest three-month stretches ever recorded in Minnesota from April to June, she said.
The second bloom does not harm lilacs. But they’ll likely have fewer flowers in the spring.
“Lilacs are very resilient,” Weisenhorn said.
The best thing to do with a stressed lilac is to water it during dry spells, clear out any fallen leaves by its roots and spread a layer of mulch at its base, she said.
Pruning also helps air and light reach its branches to ensure buds will develop in the spring.
Replumbing fields, or “tiling” them, have made southern Minnesota a vital part of the nation’s corn belt.
