If you're feeling a little flush you can get yourself some extra crop space! (What can I say? Glass is expensive!)
For 299 Horseshoes you can get over double the current space in a brand new Greenhouse Expansion. This will increase your Greenhouse space from 36 all the way up to 81 spaces.
At the moment we haven't heard that this will be available via missions, this is, for now, only a premium purchase.