Media release

From: The Royal Society

Plants in the UK flower a month earlier under recent warming

Bloomin’ hell – UK plants are flowering almost a month earlier, on average, than they did in the period before 1986. This study looked at hundreds of thousands of first flowering observations, recorded since 1793 and spanning 406 UK species, finding flowering correlated significantly with January – April maximum temperatures. Herbs saw the largest shift, flowering 32 days earlier. If plants continue to flower earlier, and climactic extremes increase, ecological and agricultural systems will be at an unprecedented risk, the authors warn.

Using 419,354 first flowering dates from 406 plant species in the UK between 1753 and 2019 CE, we show that growing seasons start circa one month earlier when comparing all observations before and after 1986. The phenological trends (5.4 days per decade) and extremes (66 days between the earliest and latest annual mean) correlate significantly with January–April maximum temperatures (r = -0.81 from 1952–2019). If plants continue to flower earlier, and if the frequency, intensity and duration of climatic extremes increase further, the functioning and productivity of biological, ecological and agricultural systems will be at an unprecedented risk.