Allows the automated growing of grass. Also used in Crossbreeding.
From tale 2:
When first built, you must seed it with 10 grass and then leave it for a period of time. Up to 100 grass will grow, then no more until it is harvested. Harvested grass remains in the greenhouse until it is taken (effectively infinite grass storage if you don't take).
Grass growth is simple - a greenhouse grows 3 grass per teppyminute until 100 grass has grown since the last time it was harvested. This process is completely linear, which means that it takes 20 teppyseconds to grow 1 grass, and 33 teppyminutes and 20 teppyseconds to grow 100 grass.
Built: small construction site
Skill/Tech required: Gardening