At first, I thought this would be a post for beginners, but realized even experts are over-indulgently inclined. Some over-riding principles: I buy organic seed when available for my organic garden, and seek out regionally appropriate varieties. Here’s why, in detail.For me, resisting buying everything requires an annual review of the basic mathematics of vegetable gardening. Now (not after 11 boxes of seeds arrive that you forgot you ordered) is the time to crunch your own numbers:How many of A, B and C plants can fit into my Y square feet (and for what cost in