Summer Solstice is an Optimal Day for Plants — But Climate Change Could Disrupt This Timing

A new study led by UBC researchers suggests that the summer solstice the longest day of the year may serve as a key cue for plant growth and reproduction. But in a changing climate, relying on this fixed signal may no longer help plants to survive or thrive.

“Plants are known to use temperature to time things like leaf growth and flowering,” says lead author Dr. Victor Van der Meersch, a postdoctoral researcher at UBC’s faculty of forestry. “This study shows that the solstice is an optimal growth period and could also be an important trigger for reproduction.”

Scientists have long known that plants use daylength to time important seasonal events. But only recently have they begun to explore whether the solstice itself  typically around June 21 in the Northern Hemisphere  plays a specific role.