Nicolas used to save many seeds. But when his variety got really big, several of these seeds grew into plants that were clearly no longer the pure heirloom breed but rather had been cross-pollinated. So, for the past few years, he had stopped saving seeds and bought from great companies like High Mowing Seeds.
His mother, Helen, continued to save a bit. And he is happy to have them. He’s going to use the tomato seeds she saved from last year. Nicolas is also going to grow a few plants in isolation in order to save their seeds.
For some breeds, like squash, different families have to be planted really far apart or to be isolated with nets. Tom, at High Mowing Seeds, does a lot of this. More and more new technologies are being developed to address this issue.