The Seeds and Crops update! (in-dev)

You can select dev-seeds (Turnip and Tomato) (Keys are Numpad 1 / Numpad 2).
You can plant down the seeds on tilled land (Key is P).
You can analyze the seeds on a farmland (Key is I).
You can simulate the growth of the seeds / crops (Key is L).

Simulating:
Seeds need water to grow, however don't disappear when they don't have water.
Crops need water to grow. If you simulate growth, the crops on the unwatered farmlands will die.
Also, Crops have to be harvested in the "HARVESTABLE" state.
If that is not being done, they will go into the "WILTED" / dead state.
If you still don't harvest them in this state, they will turn into grass.

Duration of the states (temporary):
Seeds | 4 "Days"
Crops | 4 "Days"
Harvestable | 2 "Days"
Wilted | 2 "Days"
Grass | *infinite*, since it's not a crop anymore.

Illustration:
http://puu.sh/9xrSu/0eb4ce5095.png