I would have guessed that plants might be placed by clicking, after selecting them from the menu, but that does not seem to work-- the green tree icon remains attached to my pointer and no seed is planted. What is the control for "plant seed"?
Hi, it should indeed be a simple left click for planting seeds and placing buildings! If that doesn't work, you probably encountered a bug, sorry :( Most likely there's some hidden UI blocking your mouse clicks. Did your mouse clicks work before? Thanks for the report.