Saving Heirloom Seeds

Saving Heirloom Seeds pic

During the 2014 Carolina Yard Gardening School a couple weeks ago, I took two classes and participated in two workshops. My last three posts were from the first class I took. Today, I will share what I learned in the second class I took – how to save your own heirloom seeds in such a way as to be sure they are pure and not cross-pollinated.

Before I discuss how to save heirloom seeds,  you need to know the difference between heirloom, hybrid, and GMO seed.


Most people agree that an heirloom seed is one from a variety of plant that is at least fifty years old. Most of these types of plants have been handed down from generation to generation. All heirloom plants are open-pollinated (unlike hybrids) and have stable traits and pure lines of DNA.

Heirloom varieties are the favored choice for home gardeners for the following reasons:

  • Heritage – The DNA has been passed down from older generations.
  • Future genetics – The DNA is pure, so it can be grown generation after generation.
  • Performance – The variety didn’t survive over 50 years if it didn’t perform well.
  • Sustainable – When you plant an heirloom seed, you will get the exact same plant as the parent, because it has the same DNA.
  • Taste – NOTHING tastes as good as fruit from an heirloom plant!


A hybrid seed comes from the cross-pollination of two parents of different varieties. The cross-pollination can occur naturally by the wind or bees, or it can be assisted by a gardener or researcher. With cross-pollination, a hybrid seed will have DNA from each parent and the subsequent plant (labeled F1 for first generation hybrid) will have a mixture of characteristics of each parent.

Hybrid plants are the favored choice of large-scale farmers for the following reasons:

  • Disease resistance
  • Uniform size of fruit
  • Skin thickness – to survive shipping
  • Uniform fruit ripening time (unlike heirlooms that ripen at all different times)
  • Heat tolerance

Unlike heirlooms, hybrid seeds will not give you a plant like the parent. There will be diverse, rather than uniform, characteristics. If you were to plant a seed from an F1 hybrid parent, the subsequent plant would be an F2, or second generation plant, with characteristics different from the parent. If you planted a seed from the F2 parent, you would get an F3, or third generation, plant. Although you started with a hybrid, if you continued planting a seed from each generation, you would be able to eventually produce a pure line of DNA. After F6 (sixth generation), the line would start to purify and in 50 years (F50) you would have an heirloom variety.


A GMO seed is NOT a hybrid seed. Hybrid seeds are cross-pollinated seeds which occur in nature all the time. A GMO seed can never be created by nature. Only man can create a GMO seed by injecting the DNA of a foreign species into a plant’s DNA.


If you want to save seed from your heirloom plants, you must plan your garden ahead of time. Depending on the type of seed you want to save, you may have to adjust what and where you plant. The goal is to maintain pure lines of DNA. When choosing varieties and where to plant them, you must consider the following:

  • Male vs. female flowers
  • Self pollinated vs. wind/insect/animal pollinated


Every plant has male and female parts. In some plants, the parts are within the same flower. These flowers are called perfect flowers. (Tomatoes have perfect flowers.) In other plants, the parts are in separate flowers. These flowers are called imperfect flowers. With imperfect flowers, you can tell the difference between the male and female flowers by looking beneath the flower itself. A female flower will have what looks like a miniature fruit beneath it; that’s called the ovary and will become the fruit if pollinated. The male flower has just a straight stem beneath it. The difference between male and female flowers is very noticeable on cucumbers and squash, for example.


Pollination occurs when pollen moves from the male parts to the female parts. Perfect flowers are self-pollinated, and imperfect flowers are cross-pollinated.

Self-pollination occurs when pollen moves from the male parts to the female parts of the same flower or in another flower on the same plant. The following plants have perfect flowers and are self-pollinated:

  • Tomatoes
  • Peppers
  • Eggplant
  • Beans
  • Peas

Cross-pollination occurs when pollen moves from a male flower to a female flower on the same plant or on a different plant. The following plants have imperfect flowers and are cross-pollinated:

  • Cucurbits (cucumbers, squash, melons)
  • Onions
  • Broccoli
  • Cabbage
  • Turnips
  • Cauliflower
  • Beets
  • Spinach
  • Carrots

The interesting thing about cucurbits is that many varieties will not only cross-pollinate with other varieties, they will also cross-pollinate with other species within the cucurbit family! You will have to check your variety to see if it will cross-pollinate with other species. (Purdue University has a good cross-pollination chart.)

Wind pollination occurs when the wind blows large quantities of pollen from one plant to another. Plants that are wind-pollinated have pollen granules that are small and somewhat dry, so that they are easily carried by the wind. Corn is a good example of a wind-pollinated plant. (The pollen comes from the tassels.) Because corn is wind-pollinated, you must separate varieties of corn by at least 700 feet. (Some sources suggest a half mile separation!) Otherwise, you will not only get hybrid seed, you may also get inedible corn!

Insect pollination occurs on plants with flowers that contain larger pollen granules. Unlike the dry pollen of wind-pollinated plants, these plants have sticky pollen – to stick to the insect (or animal, such as a bat, which pollinates night flowers, or a hummingbird). These types of plants attract the pollinators by their flowers’ type, structure, shape, color, scent, and nectar.


If an heirloom plant is cross-pollinated (by insects or wind), you’ll have to plant only one variety if you want to save the seed. For example, you won’t be able to plant more than one variety of cucumber if you want to save the seed.

If an heirloom plant is self-pollinated, you may plant more than one variety, but keep them separated by at least 10-12 feet if you want to save the seed.

While your plants are growing, monitor their characteristics. If a plant has a different color flower or other “off” characteristic, pull the plant up. There may have been a mutation in the DNA of the seed you planted, and you don’t want any possible mutations in the seed you collect. (On my heirloom cucumbers last year, I saw a couple of white flowers on one plant; I had never seen that before. Had I been saving seed, I would have had to pull that plant. Here’s a picture of the white (female) cucumber flower.)


  • Allow the fruit to fully ripen on the plant.
  • Choose fruit from healthy plants.
  • Take the fruit inside immediately after harvest.
  • For beans, harvest the pods when fully developed/ripe but before they dry. (If you leave the pods on the plant to dry, you risk losing the seed by the plant dropping the seed or via the weather. One year, before I harvested my dry beans, we had several days of heavy rain. My pods were ruined, and some of the beans had begun to germinate INSIDE THE PODS!) Dry the pods inside. Once dry, remove seeds from the pods and store.
  • Remove the seed from the fruit and dry. Lay the bean pods or seeds on newspaper or cardboard in a cool place with low humidity. Be sure there is space between each pod and seed. Use a fan for air circulation.


Once your seeds are completely dry, store them in a tightly sealed glass jar with silica packets. Place the jars in a cool, dry location away from sunlight. If you are storing very rare seeds, keep portions of the seeds in different locations; if something happens to one storage jar, you will still have the other.

How long seeds remain viable depends on the seed. Corn doesn’t stay viable very long, but beans and peas, when stored properly, will grow well even after long periods of storage. When storing seed for long periods, check their viability by test germinating 10 seeds in a moist paper towel. (The number of seeds that germinate will give you the percent of germination. Eight seeds out of ten will be 80%, for example.)

Heirloom plants are our future. They carry solid DNA for growing for generations to come. There are few experiences that make you feel as self-sufficient as growing food from seed you saved yourself!



Do you save your own heirloom seed? What varieties are your favorites to save? Comment below!


2 comments on “Saving Heirloom Seeds

  1. In regards to this statement, “How long seeds remain viable depends on the seed. Corn doesn’t stay viable very long, but beans and peas, when stored properly, will grow well even after long periods of storage.,” might you have switched those up? In my experience, corn seed will stay viable for several years if stored properly, while beans may only be viable for one or two years.

    • Hi, Paul. Thanks for the comment and question. Before replying to you, I decided to do a little research to check up on myself. First, I checked my notes to be sure that my article contained what I learned in class, which was taught by a representative of Clemson University; and the article does match my notes. Then I went online to several sites to see what I could find on seed viability. Virginia Cooperative Extension, Iowa State University Extension, and Colorado State Extension all stated that average seed viability for beans is 3 years, and for corn it’s 2 years. The University of Illinois Extension stated that bean seed viability is 3-4 years, and corn seed viability is 2-3 years. So, it seems that bean seed is viable for a little longer than corn seed, according to the charts, but granted – not much longer. Yet, like everything else in gardening, people’s experience can vary. Those charts are averages. I’m sure how and when the seed is harvested, and how well it’s stored has a lot to do with the length of viability. I’m just starting my seed saving journey, so I don’t have much personal experience with that yet. And what seed I buy is usually planted the first year or early the following year, so I’ve had little problem there. I’m glad you’re getting such a long “shelf life” out of your corn! I’m planting Glass Gem popcorn this year for the first time, and I plan to save the seed year to year. (I’ll be writing about that when the time comes!) Thanks again for your question. I want my readers to question me if they read something that doesn’t line up with their knowledge or experience. Gardening is one of those fields where we all learn together. Happy planting!

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