UK trees flower six months early in warm autumn

Trees flowering six months early

Horse chestnut trees across the UK are flowering and showing signs of next year's spring growth more than six months early due to mild autumn temperatures.

October warmer than average

Last month was warmer than average across all parts of the UK, marking the ninth consecutive month with above-average mean temperatures.

Stress signal from trees

Early flowering is a sign of stress, according to Dr Kate Lewthwaite at the Woodland Trust. The drought prompted trees to shut down essential systems, similar to winter dormancy.

Ecological mismatch with insects

Chris Nichols, head of conservation outcomes at the Woodland Trust, warned that trees flowering out of sync with insects creates an ecological mismatch concerning for tree resilience.

“It's like an ecological mismatch and it's concerning in terms of the resilience of trees in the long term if they're out of whack with the other species that they rely on.”

Trees confused by stress

Kevin Martin, head of tree collections at Kew Gardens, said trees went into dormancy this summer then back into growth with warm conditions, meaning they won't have buds in spring.

“The trees are all a bit confused because they've been so stressed this summer.”

Impact unknown until spring 2028

The true impact of early spring will not be known until spring 2028. Stressed trees put on little growth and are weakened, making them more vulnerable to storm damage.