Freak weather brings out an early autumn display

Autumn colours are beginning to appear on trees several weeks early as a result of the hot dry spring, the Royal Horticultural Society (RHS) has said.

While the onset of autumn is controlled by temperature and day length, the unusually early colour being seen on trees such as maples, hazels, liquidambar and laburnum is a response to the dry soils left over from the spring, the RHS said.

The society has seen yellowing, and some red and brown tints, at its gardens at Wisley, Surrey, particularly on leaves in the middle of trees which they can afford to lose without stopping much photosynthesis.

The brown foliage on chestnuts, however, is caused by leaf miner moth – which like other insects will have benefited from the warm weather.

Fruits are also ripening several weeks early on apple and pear trees, while autumn raspberries and wild fruits such as hawthorn are ahead of schedule.

Guy Barter, chief horticultural adviser at the RHS, said: “We are certainly beginning to see plants beginning to show colour because of the unusual weather we have had.”

He said a reasonably wet winter was followed by an extremely dry spring, and despite rainfall since, it had not been enough to counter extremely dry soils.

As a result, he said: “Trees and shrubs are under a lot of water stress.

“It’s not fatal because they are well-adapted but it makes them get rid of their leaves.”

He said it was not a problem for the trees, which had a very good growing season because of the early warm weather and would be in good condition for next year.

However he said gardeners should give plants such as rhododendrons and camellia a “good soak” because they formed their flower buds at this time of year and would be vulnerable to the dry soils.