An operation is under way to prune the yew hedges at an estate in Wales, and help the fight against cancer at the same time, the BBC News website reports.
The annual task at Chirk Castle takes up to eight weeks to finish, and results in about three tonnes of clippings.
They are then bought by a company which transports them to be processed into chemotherapy drugs.
The castle’s head gardener, David Lock, said it was “brilliant” to think they were helping develop anti-cancer drugs.
The drugs docetaxel and paclitaxel are developed from yew trees.
Both drugs can also be made synthetically, but yew needles are still collected and used across Britain.
At Chirk, they are bought and collected by Doncaster-based Friendship Estates, which claims they are used as the raw material for anti-cancer drugs, particularly breast and ovarian cancers.
The company’s website said clippings should be one year’s growth, because the required chemical is concentrated in greener areas of the plant.
The statuesque hedges, which line the main gardens and are dotted throughout 11 acres of grounds, were planted in 1872.
The castle, built by Edward I, is more than 700 years old and is surrounded by 500 acres of parkland.
Debbie Coats, clinical information manager at Cancer Research UK, said: “There are two common chemotherapy drugs developed from Yew trees.
“One of them, docetaxel (Taxotere), first made from the needles of the European yew. The other, paclitaxel (Taxol) and was made from the bark of the Pacific yew.
“These are used to treat some breast, prostate and ovarian cancers. Both drugs are manufactured in the lab but the needles are collected and sold to the drug industry for this purpose.”
Source: BBC News website