Among the yellow and brown clumps of fallen leaves and the skeletal frames of deciduous trees this autumn are some surprising finds: green shoots and bright flowers.
Recent mild temperatures and wet conditions have encouraged some plants that should be going into dormancy for the winter to burst back into life, experts have said, with possible disruptive effects on nature’s cycles.
The apparent second spring has come after the UK recorded an unprecedented 10 months of above average temperatures, following a record-breaking summer heatwave.
“Recent mild conditions and plentiful rain will have encouraged unseasonal plant growth,” said John David, head of horticultural taxonomy at the Royal Horticultural Society.
He added: “This summer caused quite a few plants, shrubs and trees to lose leaves or die down to survive the heat and drought. It was noticeable that when the rain returned in September quite a few plants produced new leaves that would not normally do so at this time of year, and some also came into flower again.”
David said the autumn had so far been “exceptionally mild”, and that RHS Garden Wisley, in Woking, Surrey, still had not had an air frost.
“The mild weather seems set to continue, as we are experiencing a series of deep low-pressure systems coming across the Atlantic bringing warm, humid air,” he said.
The north of England has also had unseasonal weather, with one gardener at a National Trust property there reporting fuchsias and dahlias blooming into October. Since then a frost had “knocked things back”, he said.
“Certainly we noticed extremely mild weather around October, and that kept prolonging things,” he added. “It can be problematic if you don’t have a proper dormant period, at some point, over the winter.”
Powis Castle and Garden, near Welshpool, in Wales, said its strawberry tree, Arbutus unedo – one of the largest and oldest in the country – had produced double the amount of fruit this year, the first time the gardening team had seen such an increase.
Ned Lomax, head gardener of Bodnant Garden, in Conwy, said: “We do have a few plants flowering out of season, mostly rhododendrons but a couple of other things, too. Some plants are actively growing or flowering now as a response to the mild and wet weather following the long, dry, summer when growth wasn’t possible due to the harsh conditions.”
The horticulturist Alys Fowler said many plants were “having a second go” at flowering. “I have a bramble in my garden that is doing just that,” she said. “And roses often will throw out a flower or two in winter if the weather is mild. Many plants are opportunists – if the temperature is right and the day length OK … they will have a go. I guess there is some evolutionary advantage to that. Are we seeing more of it because of climate change? Yes, for sure.”
Plants with the genetic predisposition to benefit from the current climatic conditions were doing so, Fowler said. But plants that relied on colder temperatures could suffer, and there would be knock-on effects along the ecosystem.
“If you are a pollinator with an evolutionary reliance on certain plants or temperatures being predictable at a certain time, then warm autumns are problematic,” Fowler said. “You don’t go into hibernation at the right moment or you wake up too early with nothing to eat. Like all the peacock butterflies right now.”
The UK is due more rain in coming days, Met Office forecasts say, with temperatures expected to drop closer to the usual average, so the second spring might not last. But its effects could be far reaching.
