Blog: Don’t be fooled by the early changing colours and ripening berries – climate change is key
As tree leaf colours change early, you’d be excused for thinking we are having longer autumns, but more accurately, it’s a false autumn. Berries are ripening early, and leaves are falling due to the extreme stress of drought this spring and summer in the UK, due to climate change.
True autumn has two definitions: meteorological autumn, which spans from September 1 to November 30, and astronomical autumn, which begins at the equinox on September 22 and ends at the winter equinox on December 21. False autumn is when meteorological conditions prompt plants to shut down early for the winter, thus shedding leaves and early fruit ripening in August.
This summer was the UK’s warmest on record, with a mean temperature of 16.10°C, surpassing the previous record of 15.76°C set in 2018. Several factors contributed to the warmth. June and July saw above-average temperatures, with England recording its warmest June on record. Four heatwaves were driven by persistent high pressure, centred over the UK or extending from the Azores.
A dry spring left the ground parched, and a marine heatwave meant sea surface temperatures were well above average. This perfect storm created an environment where heat could build and stay. Minimum overnight temperatures were also above average. The UK is warming at about 0.25°C per decade, having a significant effect on the health of native plants. Figures courtesy of the Met Office.
Causes of false autumn
- Drought conditions cause trees to enter survival mode, dropping their leaves early to conserve water and energy. While not dying, they’re not actively growing or thriving. Mature trees have extensive root systems to survive; however, young specimens may die due to lack of moisture.
- High temperatures can make matters worse, forcing them to drop leaves early. The UK’s broad-leaved native trees are particularly prone to damage in hot, dry summers – they have not adapted to cope with such conditions.
- Extreme weather patterns also contribute to the phenomenon. Last year was particularly wet – warmer air holds more water – so plants have to cope with extreme and conflicting weather patterns.
How my garden has been affected
The most noticeable sign of false autumn is my beech hedge, which has been turning gold since mid-August. Acer Jordan’s leaves are quickly turning and dropping, although Trompenburg, in a more sheltered, shadier spot, is not too bad. My Brown Turkey fig has hated the lack of water. It dropped its fruit as well as some of its leaves. Even the late herbaceous perennials haven’t performed well, due to lack of water (I try not to use a hose).
However, look on the bright side – the drought-lovers (geraniums and succulents) have had a cracking year. It just goes to show – always grow plants for every eventuality. You’ll always have something you can be proud of.
Even now that we are getting much-needed rain, it’s too late to stop the process of leaf fall. Early gales have been a feature of August, so much so that falling apples dented our new car!
