Oct. 7, 2019. In this interesting story by Heather Brown of WCCO TV News, she talks to a Circle Pines, MN gardener with lilacs reblooming – in October! She interviews Julie Weisenhorn, an associate extension professor at the Department of Horticulture at the University of Minnesota who helps us understand this unusual phenomenon. Only the Lilac variety ‘Bloomerang® Purple’ typically blooms again.
Read the article below or watch the video at WCCO.
MINNEAPOLIS (WCCO) — October 7, 2019. It might be autumn, but WCCO viewers are seeing flowers that don’t normally bloom this time of year.
Bill sent in a photo of lilacs blooming in Circle Pines, while Jodie sent in a similar photo from New Prague. So, they want to know: Why are plants blooming in October? Good Question.
About a week ago, Julie Ackerman noticed one of her lilac bushes outside her Circle Pines home was blooming.
“It was the first time in 18 years we’ve been here,” Ackerman said. “I thought maybe they thought it was spring again.”
WCCO brought the photo to Julie Weisenhorn, an associate extension professor at the Department of Horticulture at the University of Minnesota. She said there are some lilac bushes that rebloom in the late summer, but these blooms are more likely due to Minnesota’s recent weather patterns.
“We’ve had warmer temperatures, but we’ve had cool temperatures, so it’s that fluctuating temperature that prompted those plants to bloom,” Weisenhorn said.
She said she hasn’t seen lilacs bloom in the fall, but said she seen it with azaleas. Those spring-blooming plants set their buds a few weeks after they bloom each spring. Generally, they bloom a year later when triggered by the weather.
“It’s actually a hormonal response to the weather — the temperature and the light,” Weisenhorn said. With the cooler late summer and warmer September, Weisenhorn suspects the flowers confused the fall for spring.
Ackerman wondered whether a recent lawn treatment might have triggered the fall blooms. But according to Theresa Rooney, an Extension Master Gardener in Hennepin County, that’s very likely not the case.
“It’s more likely the environmental stress,” Rooney said. As for why only one plant in a row of several might bloom, Rooney added each plant is different. Some are more stressed or weaker compared to others.
As Minnesota’s weather patterns continue to change, Weisenhorn said there’s a possibility more plants could bloom in the call.
“We could,” she said. “We’re not really sure, it’s a lot of things fluctuating and changing.” But, she says people shouldn’t worry if their lilacs bloom in the fall. While they likely won’t rebloom that spring, the plant will be OK.
Heather Brown loves to put her curiosity to work to answer your Good Questions on WCCO 4 News at 10, and helps you kick your weekdays off on WCCO Mid-Morning.