The contract will last for five years with a possible two year extension and part of the deal will see Glendale work with head gardener Peter Norman and assistant head gardener Andy Gauld to oversee grounds upkeep and development for all three gardens.
Specialist work at Richmond Castle and Mount Grace Priory in north Yorkshire and Barnard Castle is in County Durham includes looking after formal lawns; caring for herbaceous borders, rose beds, alpine beds and creepers.
Teams will clip formal hedging and topiary and the programme will see Glendale support English Heritage in developing the sites and provide year-round features, said the grounds management company.
"One of the key sites that Glendale will be responsible for is an elegant herb bed behind a reconstructed Monks Cell at Mount Grace Priory," said regional support manager David Fontana. "The bed is part of the site’s heritage, teaching us how monks lived 600 years ago."
"We are delighted to work in partnership to preserve such prestigious sites and look forward to demonstrating our expertise in specialist horticultural and grounds management. We will help English Heritage in restorative and conservation activities."
As the partnership develops one of Glendale’s key objectives is to review and develop management plans for each of the three sites and push forward long-term sustainability plans, he said.
English Heritage runs around 400 sites across the UK, most of which have gardens that help draw more than 11m visitors every year. The annual contract value is £64,000.
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