Heirloom, Hybrid & GMO Seeds: What’s the Difference?

When did gardening get so complicated, so . . . controversial? So full of decisions? Should you buy hybrid or open-pollinated seed? What is an heirloom seed? Does it matter which company you purchase from? Must seed be organic? And what about GMOs?

Hybrid, Open-Pollinated, and Heirloom Seeds

Open-Pollinated Seeds

I’ll do my best to make your decision making process easier.

Let’s start with open-pollinated seed. This simply means that the plant has been pollinated naturally by insects, wind, or birds, for example. Seeds saved from thee plants will produce plants just like the parent plant as long as no cross-pollination has occurred.

Squashes, for example, cross-pollinate easily with other varieties of squash. If you save seed from a butternut squash that was grown near an acorn squash, the resulting plant may not be “true to type.”

Other vegetables, such as tomatoes, do not easily cross-pollinate; saving seed from your favorite variety will continue to produce that variety.

Companies and individuals who are in the business of saving seed take great pains to prevent cross-pollination from occurring so that the seeds they sell will be true.

Heirloom Seeds

Heirloom seeds are always open-pollinated, but not all open-pollinated seeds are heirloom. I have heard it said that heirloom seeds are open-pollinated seeds with provenance. The seed has been saved and grown and protected through many generations, and that history is preserved along with the seed.

Hybrid Seeds

With hybrid seeds, pollination is tightly controlled and the plant is bred to have very specific traits. For example, a very tasty tomato may be crossed with a tomato that always produces an early crop to form a new hybrid variety that is both delicious and early.

Disease resistance is very often a characteristic that is sought after in hybrid seeds. Seeds saved from hybrid plants will not not produce true, but will have the characteristic of one parent plant or the other.

Seeds must be re-purchased each year to maintain the desired traits, although hybridization is something that a serious gardener with the right knowledge could actually do on his own.

Whether to purchase open-pollinated or hybrid seeds is not always a simple answer. In general, I prefer open-pollinated seeds. If you wish to save your seeds, this is the only option.

I am concerned that we are losing many old and valuable varieties of seeds, and I want to help to preserve as many varieties as possible.

In 1903 commercial seed houses offered 408 varieties of tomato seed. By 1983, that number dropped to 79 varieties. The less diversity we have in plants, the greater the risk that disease will wipe out entire crops.

The Irish Potato Famine is a good example of the horrendous disaster that can occur when only one variety of crop is planted. This one variety was susceptible to potato blight; not only was a crop wiped out, but a million people died and a million more were forced to emigrate. Planting a wide diversity of potato varieties could have prevented this tragedy.

There are times when certain crops simply do not thrive in a given area. I struggle to consistently grow disease-free heirloom cucumbers in our high-humidity weather. I keep trying, but I plant a few disease-resisitant hybrid seeds as well to insure that I don’t lose my entire crop.

This is not to say that heirloom seeds never have disease-resistant qualities. I keep trying different varieties, and I hope to find one that proves consistently successful.

I have also found that planting my cucumber seeds a week or two later than normal really helps to prevent disease spread by cucumber beetles.

Genetically Modified Seeds

What about GMO seeds? Genetically modified seeds are not to be confused with hybridized seeds. According to Penn State Extension,

Genetic engineering allows the transfer of one specific gene or a small set of genes within a plant family or across species lines. It is possible to transfer genes from animals, bacteria, insects, or most any living organism into plants.

Genetic modification involves the transfer of genes from one species to another in many cases.

Genetic modification is very controversial, and the internet is full of arguments for and against its use. While I don’t find it necessary to get into the arguments here, suffice it to say that genetic modification has no place in the organic garden.

At this point, there is no worry in finding genetically engineered seeds in a home gardening catalog. They just aren’t available for the home grower yet.

Corn and squash have been genetically modified, but the seeds are only available to farmers. (If you live near a farm that is growing genetically modified corn or squash, and you are growing these vegetables yourself, do not save seed from these plants since cross-pollination from the farmer’s plants will most likely contaminate your seeds.

Tomatoes and potatoes have been genetically modified but are not yet available commercially. Does that mean that you do not have to concern yourself with genetically engineered seeds or from which company you purchase your seeds?

Well, like everything else in this world, it’s not so simple. The leading producer of genetically engineered seeds is Monsanto. In 2005, Monsanto acquired Seminis, owner of many of the seed companies that cater to home gardeners.

Even if these companies are not selling genetically engineered seeds at this time, you are supporting the process by buying from these companies. For a current list of Monsanto-free seed companies, please do an internet search. The lists change too frequently to provide a link here.

Organic or Not?

Another consideration when purchasing seeds is whether or not the seed must be organic. As I write this, I cannot help but wonder how topics such as food and gardening have become so complicated.

It’s not just a matter of saying yes, buy organic. There are farms that are not certified organic where I would much prefer to purchase food than others which are “organic.” Practices are diverse, and some farms practice the bare minimum required to be certified but are not careful to build healthy soil.

So, in my opinion, choose a good company whose goal is to preserve our seed heritage in a sustainable manner. This company will likely carry both certified organic seeds and those which are not. Purchase either. I personally purchase heirloom seeds from Seed Savers Exchange.

To learn how to build a garden that builds healthy soil, be sure to check out my eBook The Art of Gardening: Building Your Soil. 

All of the beautiful watercolors of seed packages in this post are by Deb Hamby and are included in this eBook.

You really can become a better gardener, and you really can grow healthy, nourishing produce. It’s all about the soil! Click here to learn more.

More Great Gardening Posts

How to Build a Lasagna Garden

Your Seeds Aren’t Germinating: Here’s Why

Using Wood Chips in a Vegetable Garden

Growing Tomatoes: From Seed to Harvest

The Easy Way to Grow Raspberries

How to Grow, Harvest, and Cure Garlic

The Ins and Outs of Using Manure in Your Garden

Edit regarding ads for Monsanto or Bayer that have occasionally popped up on this post: I have not seen any myself. It seems that they are showing up because this post mentions GMOs. I have spoken with my ad company and they explained that while they have blocked ads from Monsanto and Bayer on my site, that only takes care of about half of their ad partners. Every ad has a “Report this ad” button under it. Please do use this if you see Monsanto or Bayer ads on this site as that will help to eliminate any stray ads that may pop up on my site. Thank you so much!