The contract is a significant win for the company after losing its work at the London Borough of Camden to Connaught. The 10-year deal was discussed at the council's overview and scrutiny committee meeting on 17 November.
Parkwood Holdings executive chairman Tony Hewitt told HW it meant a lot to the firm, which owns Glendale. "It is our flagship contract in the South East and London," he said. "It was the first real partnership contract in the country and we are delighted to have won it again."
The firm picked up a Horticulture Week Landscape & Amenity Award for partnering in 2007 based on its relationship with Lewisham. The council's green space regeneration manager Martin Hyde and Glendale regional director Adrian Wickham work closely on the contract.
Glendale is tasked with delivering 20 green flags in the borough by 2020 - up from 10 this year.
The value of the contract has not been finalised, but it was estimated at £35m in tender documents. Hewitt confirmed that it would be worth around £4m a year but was likely to vary depending on the work required.
"There is always a fear you won't win back a contract, but ultimately we were the successful party," he said. "London is a very competitive marketplace."
Glendale has also picked up a contract valued at almost £3.9m with Nuneaton and Bedworth Borough Council. It beat four other bidders to win the five-year deal.