If you look carefully on the page where you can buy the Stones Throw Greenhouse, you'llo notice that if you scroll down a bit (next to where it shows you what items you get along with this set), on the right side, it says:
" * Please note that you need FREE game update 1.5.0.019000 in order for this content to work. "
So, I'm guessing that before such time that this update is issued, you probably won't be able to plant anything INSIDE the Greenhouse. And seeing as we're only at about Update 1.42 - ish, there's still some time...
