00:00If you've been out in a park or garden recently, you may have noticed something that looks out of place.
00:05Brown leaves on the ground, bad patches in the trees and vegetation taking on the colours we normally associate with
00:12autumn.
00:13This is a phenomenon known as false autumn caused by trees and plants responding to extreme weather.
00:19Leaves have begun to brown and fall at parks in Bristol, while photographs from locations across the UK show scenes
00:25that would usually be associated with the middle of autumn.
00:28Four-time Chelsea Flower Show gold medalist John Massey says he's noticed the early changes.
00:34He describes the browning of leaves as a response to extreme stress, with long periods of hot and dry weather
00:40contributing to the effect.
00:42But his message for gardeners is reassuring. He says there's a good chance plants will bounce back next year.
00:48Kai Barter, chief horticulturalist at the Royal Horticultural Society, says some trees are losing their leaves because of drought stress.
00:56He explains that some have already shown red and golden colours, creating the appearance of autumn.
01:02However, the RHS distinguishes this from what happens during a normal autumn.
01:07Around October, trees naturally discover nutrients from their leaves before they fall, revealing the colours associated with the season.
01:16That means an early fall of leaves is not simply a change in the calendar.
01:19It's a sign some trees are struggling with the conditions around them.
01:23Prolonged dry weather can push trees into a survival response, with leaf loss helping them conserve water and energy.
01:31Younger trees can be particularly affected because they may not have deep root systems capable of reaching moisture further underground.
01:38High temperatures can add to that pressure, increasing the stress already caused by a lack of water.
01:43The Met Office described this summer as one of exceptional warmth, with four heat waves and above average temperatures.
01:50England recorded its warmest June on record, while a dry spring left the ground parched.
01:55The Met Office has also identified unusually warm sea temperatures around the UK and persistent high pressure,
02:00as factors that help maintain the hot, settled and dry conditions affecting trees and plants.
02:07There's also a wider climate context in the information provided.
02:10The UK is described as warming by about 0.25 degrees Celsius per decade,
02:16while increasingly hot and dry conditions are identified as contributing to more frequent episodes of stress in trees and plants.
02:24But the appearance of false autumn does not mean every tree is in serious danger.
02:28Guy Barter says enough trees have retained their foliage for there to be a somewhat diminished display of true autumn
02:33colour later this year.
02:35The RHS says stress trees will probably recover in spring, although some tree death next year and in subsequent years
02:41cannot be ruled out.
02:43So while a scattering of brown leaves in late summer may look like an early change of season,
02:49the message from gardeners and horticulturalists is that instead it's a visible sign of how strongly extreme weather can affect
02:57the natural landscape.
02:59The RHS says it's a visible sign of how strong weather can affect the natural landscape.
02:59The RHS says it's a visible sign of how strong weather can affect the natural landscape.
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