zasaditi

1. to plant
   Prošle jeseni smo zasadili tri trešnje u dvorištu. — Last autumn we planted three cherry trees in the yard.
2. (of a plot of land) to plant with
   Deda je zasadio celu njivu kukuruzom. — Grandpa planted the whole field with corn.

The imperfective is zasađivati; for a single plant posaditi is more common.