Reforest: Old Growth expands the original game and acts as a storage solution for the Reforest series. 

It can be combined with Reforest: Plants of the Pacific Northwest Coast or played as a standalone game.

New elements introduced in this expansion include:
- Old growth trees than can reveal previously covered effects and regenerate stored plants.
- Parasitic plants that can be played freely but feed off of existing plants.
- Terrain cards that offer growing benefits to your elevation rows.

Reforest: Old Growth adds complexity. New players should begin with the original game; Reforest: Plants of the Pacific Northwest Coast.