Invasion of the Star Creatures.

Beautiful alien Amazonian women plan to conquer the world using an army of vegetable monsters. Dim-witted privates Philbrick and Penn bumble into a cave in search of atomic activity but collide instead with fierce carrot-topped tree mutants and their leaders, the 7-foot space sirens Prof. Tanga and Dr. Puna. This lavishly low-budget sci-fi romp has the bodacious aliens planning to overrun Earth with their vege-men army, but first they want the G.I.s to explain the meaning of love.