HLF has awarded the money towards Epping Forest's £6.8m Branching Out project. The scheme will get underway in the autumn and should take five years to complete, said Epping Forest chairman Wendy Mead.
The funding will support the development of a new interpretation centre, three remodelled visitor hubs and marked trails.
In addition, around 750 schoolchildren each year will benefit from the education programme Discovering Epping Forest, which will give them the experience of outdoor learning.
The City of London will work with Capel Manor College to employ 15 apprentice arborists over the life of the project. The extra help will allow for increased tree management, and the apprentices will be learning techniques specific to the management of veteran trees.
Mead said: "This funding will allow us to achieve many of the much-needed changes in a much shorter period of time than anticipated. It will also help us develop open-space access and education and learning for future generations at Epping Forest."