Well, the food is in the environment. I would like to compare it with how bacteriae feed (however my biology is quite rusty), that is, they engulf their food and they "digest" -- not the proper term, since there are no organs to do real digestion -- it.
Answer:
Sprouting is the natural process by which seeds or spores germinate and put out shoots, and already established plants produce new leaves or buds or other newly developing parts experience further growth.
