Zynga hopes to change this in the near future however, as they have announced via the official FarmVille Blog that soon, Orchards will begin producing Water for users to use for the Mystery Seedlings. In a nutshell, this means that if you don't receive a Mystery Seedling when harvesting an Orchard, you'll receive Water instead (as well as the normal coins).
It hasn't been announced how much water you'll receive for each Orchard, but we'll take anything at this point. Orchards should begin producing water next week - bring it on Zynga!
Will you start collecting more Mystery Seedlings now that Orchards will be able to produce water for you to grow them? Let us know in the comments.