Drought plays tricks with flowers, bushes

  • Published: Wednesday, Sept. 23, 2020

COLUMBIA, Mo. – Persistent dry conditions may trick plants into dormancy and blooming with a second, sparser round of flowers, says University of Missouri Extension field horticulturist Patrick Byers.

Re-blooming generally happens when the plant experiences stress followed by mild weather and precipitation.

Gardeners, especially those in dry parts of Missouri, reported these untimely blooms during recent virtual town hall meetings with MU Extension horticulturists.

Southwestern Missouri and other pockets of the state saw moderate to severe dryness this year. Springfield reported only 4.98 inches of rain in the 97-day period of June 11-Sept. 15. That is the third-driest for that specific period in 133 years, says MU Extension climatologist Pat Guinan.

Plants rely on environmental clues to know when to flower. Light, temperature and precipitation work together to signal the right time for flowers, bushes and trees to bloom.

Plants become confused when these things get out of sync, such as when rainfall levels drop. “The process gets short-circuited,” says Byers.

The dryness sends a cue that fall and winter are on the way. Plants go into a dormancy of sorts, says Byers. When mild temperatures and rainfall follow, plants begin to bloom.

The second blooms are often fewer in number and sometimes not that noticeable. Fortunately, the second blooming does not affect plant performance the following spring, he says.

For more information on gardening topics, go to MU Extension’s Missouri Master Gardener website at mg.missouri.edu.

Writer: Linda Geist

Media Contact

Patrick Guinan
573/882-5908

Patrick Byers
417/859-2044

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