The Royal Parks, which won nearly £1.5m of lottery money last week for an internationally noted woodland, will use the money on training and green initiatives.
Chief executive Linda Lennon said the cash would pay for two 18-month horticultural apprentice placements for school-leavers, who could then move on to the highly-acclaimed Royal Parks apprentice scheme.
The grant from the Heritage and Big Lottery Funds will be used on the Isabella Plantation in Richmond Park. The 17.5ha garden is famous for azaleas and rhododendrons and draws more than 300,000 visitors a year.
A crucial change will be the use of a sustainable off-grid heating and lighting system. Locally-grown wood will be used to generate power. Meanwhile, an irrigation system will use water harvested from the park's natural supply.
A network of fully accessible paths and a toilet block and shelter will be built, while a disabled car park will be resurfaced. Funding will also enable education, community and volunteer activities to continue.
Lennon said: "By creating more varied conditions and a more diverse plant community, we will improve the habitat for resident species."
The SITA Trust also awarded £120,000 to fund work on ponds and streams, including silt removal and new areas of planting.
"This award will increase biodiversity, add to the collections of rare plants and make the area accessible for everyone. Richmond Park can now join in with the biggest programme of park restorations since Victorian times, which has seen no fewer than eight major re-openings in London this year."
Wesley Kerr, London chair, Heritage Lottery Fund