Why the Indian summer may mean holly without berries this Christmas

Think roast turkey without stuffing. Or the pudding without brandy butter. Tragic, but it may be about to happen this Christmas: holly without berries.

Across much of Britain, bright red berries are already fruiting on holly trees and being picked off by grateful birds - several weeks early. The implication is that, by 25 December, there may be few if any left.

The berry bonanza is part of one of the best seasons for wild fruits, berries and seeds for many years, caused by an ideal succession of weather from spring through to autumn.

Big clusters of scarlet berries from other shrubs and trees, from hawthorns to rowans, are brightening many hedges, which are laden down with blackberries, while acorns are particularly plump and numerous on oak trees. It has also been a bumper season for apples.

The rich harvest has been caused by a very favourable sequence of weather events during the course of 2006. Firstly, a late spring meant that when blossoms appeared on the trees in May, the time of spring frosts that might kill them was already past.

Most of the flowers were pollinated by the large number of bumblebees and other insects that flourished in the warm weather that followed.

The record heat of July then kick-started the ripening process, while the wet weather of August allowed the fruits and seeds to swell. Then their ripening was completed by the Indian summer of September and October.

"It's been an ideal year for fruits and seeds," said Tony Kirkham, head of the arboretum at the Royal Botanic Gardens, Kew. "In fact, it's probably one of the best seed years I've ever seen." Kew's own hollies were "spectacular", said Mr Kirkham, who added that the berries were about six weeks early.

He said "I have a holly tree in my garden and the other day it was covered in woodpigeons which were stripping it bare. Normally, the berries are food in the midwinter for redwings, the migrant thrushes from Scandinavia. I doubt there will be any left for them. And I suppose it's possible that there will be few holly berries left for Christmas."

Trees were also fruiting well because they were under stress from the droughts of the last three winters, Mr Kirkham said. "Stressed plants tend to flower better," he said. "It's Nature's way of preserving the species."

Nick Collinson, head of conservation policy at The Woodland Trust, said. "No frost on the flowers, then masses of insect activity for pollination, a hot July and a lovely moist August - all perfect for fruit ripening."

"The resident birds have a glut of fruit in the trees now, but it may be harder for the migrant birds that come in the winter".