CLIMATE change is wreaking havoc in the region's gardens with infestations of pests which suck the life out of prize plants.

Recent years have seen parasites such as greenfly - Latin name macrosiphum rosae - and whitefly thriving, and experts believe a succession of mild winters is a major cause.

Some gardeners have reported particularly large numbers of whitefly this year. Like greenfly, it sucks the sap out of plants, making them wilt and often die.

They are particularly fond of geraniums, fuschias, cabbages, tomato, cucumber and pepper plants and can often be found in greenhouses.

Mark Blake, co-manager of Elm Ridge Garden Centre, Darlington, said: "The bugs are appearing earlier in the year because of the recent mild winters. We used to be able to rely on nature and a sharp, harsh winter, but the bugs seem to be over-wintering better.

"We used to have people coming in for bug killers during July and August, but now it is more or less all year round."

Mr Blake believes that moves to outlaw more lethal chemical treatments in favour of milder, more environmentally-friendly, ones could be helping the insects.

Previously, a spray could keep a plant free of bugs for four to six weeks, but now spraying needed to be done every three days.

Another factor could be the increasing practice of taking plants inside for the winter, allowing the bugs to survive.

Robin Jaye, manager of the gardens at Hardwick Hall, Sedgefield, County Durham, said the pests may be building up immunity to chemical sprays.