We probably ought to begin by explaining some terminology. An heirloom plant variety is a variety that you can save seed from, plant it, and get essentially the same thing again generation after generation. The alternative is a hybrid variety, which if you were to save seed from, you'd get something not quite the same as the previous generation: maybe a different color or shape, often less productive, probably a different taste or texture, etc. So, for example, the seed of an heirloom 'German Johnson' tomato should yield another 'German Johnson,' but the seed of a 'betterboy' (which is a hybrid) would yield a tomato that might more closely resemble one or another of the parent lines that were crossed to yield the 'betterboy' or some very different cross. So the most basic thing to understand is that for the gardener or farmer growing hybrid plants means going back to the seed company to buy more seed every year, whereas with heirlooms there's the potential to isolate a variety (from other varieties of the same species it might cross with) and save seed to replant.
We grow pretty much exclusively heirlooms (or more accurately “open-pollinated” varieties which includes all heirlooms.) Even those crops that are almost always hybrid, like corn, onions, broccoli, bell peppers... even with those crops we're growing heirlooms instead. So why grow heirlooms? There are a lot of little reasons. Heirloom varieties were often bred for taste; modern hybrids are often bred more narrowly for productivity or traits like suitability to picking under-ripe and shipping long distances. Heirloom varieties are often more suitable to simple organic growing methods; modern hybrids are often bred specifically for use with heavy applications of purchased fertilizers, intensive irrigation, and other chemicals and plastics. Of course, heirloom varieties also allow us to save a lot of our own seed, which means we can be more self-sufficient and grow a product with more local value. Saving our own seed means we don't have to worry about buying seed that might come treated with chemicals we'd rather not use. It means we can grow varieties that originally came from 50 different sources without having to pay separate shipping and handling to 50 different seed companies every year, because if we can save our own seed we only need to get it here once, so overall it means that we can grow a greater diversity than we could otherwise. And when we save seed from an eggplant, instead of a packet with 30 seeds, we have 10,000 seeds, which means we can share with friends and neighbors and other farmers, and they can often share with us. We wrote last week about the field peas that came from Eric's great uncle. Another pea variety came from friends at church and another variety from a customer. We're growing yacons and roselles (wonderful crops that we didn't even know about), sweet potatoes and tomatoes from friends in Rutherford County, another tomato from Melissa's mom, rhubarb and field corn from Eric's former workmate in the Brushy Mountains, beans and butterbeans from a farmers' market customer, peanuts from a friend in Virginia peanut country, etc., etc. Many of these seeds came with working knowledge of how to grow them. What all this amounts to is independence: heirlooms mean the potential to eat the kinds of crops and to farm in ways that aren't determined by corporate profitability. And as much as anything, what we want to offer to you is a real alternative to the corporate food system.