I am definitely no expert when it comes to this. In fact, I'm only a couple of years into this journey. Although I've been gardening for many years (about 8), I never really thought too much about where my seeds came from. I was only concerned with growing organically. Until a couple of years ago when we moved to the country and started getting really serious about it. While organic is good, it needs to go much deeper than that.
Many of you have probably heard of Monsanto. Or Genetically Modified Organisms. I haven't done a whole lot of research on them cause I'd rather spend my time researching what I DO want to learn, not what I want to stay away from. I have instead invested my time into learning how to grow heirloom organically, and how to harvest my own seeds. All I really know about Monsanto and GMO, is that it's bad news and I don't want anything to do with it. So, THIS is not that kind of post. I DO want to help you understand WHY heirloom is more important than organic when you pick out your seeds to start your next growing project.
Short and sweet answer is that Organic can sometimes still be a hybrid. Or a cross. If you plant a hybrid, the seeds that you will get from it are unstable. Meaning, you won't necessarily get the same thing that you got the seed from. I like to use the reference of people and babies. Two people can have multiple babies, but they are not exact replicas of each other. Each child will have a unique personality and appearance. Well, a hybrid plant will produce multiple kinds of seeds, or no seeds at all (seedless grapes, watermelons, cucumbers, etc) in which are unpredictable and unstable. If you only intend on planting and not collecting seeds for future use, then it's not too much of an issue. Just know that you will have to repurchase your seeds the next time you plant (as is the case with GMO or Monsanto seeds). This is not a self sustainable way of gardening.
Heirloom will produce seeds that you can harvest to plant future gardens with, indefinitely. However, you will need to take precautions to make sure that similar plants don't cross, or become a hybrid. You'll want to learn what plants self pollinate and rarely cross, and which plants are pollinated by bugs and bees and sometimes get crossed, as well as how to prevent crossing. Some plants are even biennial. Meaning they don't go to seed until the 2nd year. For those, you'll want to learn to properly store over winter so that you can plant them back out and gather seeds the following year. This IS a self sustainable way of gardening, and one that is becoming lost. ( For more information on how to collect seeds and prevent crossing of species, please see this link at Seed Savers.)
Most people just go to the store and buy seeds, or to a greenhouse and buy plants. But what if that were not available? Would you know how to grow, harvest, and store in order to feed your family? While gardening can be great fun and a very enjoyable hobby, it is also a very important way of life. It is your backup plan in case it's ever needed! And truly, it is becoming a lost art. If it seems so unusual for US, how do you think it will be for our children and grandchildren to be able to feed themselves?
Even if you only plant a couple of pots of something, or some herbs, I encourage you to learn about heirlooms and seed harvest. Just in case it could ever be useful! :) We are less than a hundred years since this was THE way of life! No grocery stores existed! How quickly we forget!
So, this year when you start planning your garden, please consider incorporating some heirloom varieties. Two of my favorite companies are Seed Savers, and Baker Creek Seed Company although there are several more as well. Just look for the key word of Heirloom.