That being said, the bonus for May will be any seeds in Tier 0.
I'll take a look at the other Tiers and see about increasing the choices available by moving some that have been around for a bit. Also, I'm going to make another Mixed Capes envelope for Tier 0, that seemed to be pretty popular with new growers. Virtually instant results (after a couple of weeks waiting), then just about instantaneous.
Edit: Maxsea is still available as a bonus, however it is available to experienced growers only. The donors loophole does not apply to Maxsea. Seeing as how it is spring, plants are going outdoors, bugs are waking up, there should not be a need of it to the casual growers.