Heirloom garden vegetables are those that have not been genetically modified and thus made into “hybrid” plants. Storebought garden seeds are almost all “hybrid” types that have been cross bred to produce larger, sweeter, or “better” fruit from the plant, which they do. The only problem, for long term survival purposes, is that these storebought hybrids won’t produce their fruit in following years from the saved seeds. Heirloom plants, however usually produce a somewhat smaller crop, but will produce their fruit year after year indefinitely, thus you will have garden food on a yearly reoccuring basis with heirlooms. I have found out one thing about heirloom seedlings when transplanting them from pots to soil in the spring. The heirlooms are much more “touchy” and have weaker beginning stems than do the hybrid plants, so be extra careful when removing them from your seedling pots so as not to damage the roots. Also take a bit more care in packing them into the soil so that you don’t break the stems. After they “take off” in about a month they seem to do just fine, but a little “TLC” in transplanting them is in order.