Unusual weather causes rare September lilac bloom in Minnesota

RICHFIELD, Minn. — A popular spring flower is giving an unusual encore in September. Lilacs have been spotted blooming for a second time this year in neighborhoods across the Twin Cities and beyond.

Erik Bergstrom with the Minnesota State Horticultural Society has a lilac bush in his Richfield yard. It recently bloomed too. 

“Having no water and having this heat has really confused a lot of our plants,” Bergstrom said.

He said the late bloom is a sign of stress from extreme weather swings. Minnesota saw years of drought, and more recently, a wet spring and summer followed by what could be a historically dry and warm September. 

Bergstrom said the untimely bloom won’t hurt the plant. It will still bloom in the spring, though there may be fewer flowers.

“You don’t really want to do any pruning right now because of the buds that are still not open yet, you want to keep those for next spring,” he said.

If lilac leaves turn brown and drop, he said it’s likely a fungal disease that could have been sparked by wet weather. 

“You want to rake them out and not compost them, either burn them or throw them in the trash so that the fungus doesn’t come back the following year,” he said.

Minnesota Grown said they’ve heard from farmers who are happy to have dry weather so families can enjoy fall activities, adding pumpkins do well in the dry conditions too. Some apples may be larger this year because of heavy spring rain, but it varies by region.