a) The "buy" page screams out for some pics - people eat (and buy!) with their eyes :).
b) "We choose seeds that are perfect for your climate and the time of year" then the next page asks me to select my own choices? A little confusing - maybe you're building a list of options dynamically?
c) Consider for future "upsells" on the buy page or a more expensive $99.95 starter pack that includes soil, pots, etc. for people that have zero knowledge but like the idea - not sure if that's your audience or people already gardening?
Great concept and I think you're on the right track - a "starter pack" would have got my money.