You are here: home / activities / PASS / John Coykendall's article on Mintaining Seed Purity

An Article by John Coykendall who has donated many seeds to SSLP

MAINTAINING SEED PURITY

For a number of years now I have been collecting rare and endangered heirloom vegetable crop varieties and growing them out for seed production and preservation. I am also a listed member with Seed Savers Exchange, located in Decorah, Iowa, which has over 18,000 heirloom varieties in its seedbank collection.

As my own collection has grown over the years, one of my greatest concerns has been the problem of maintaining seed purity, or the prevention of cross-pollination during grow-outs each season. Over the past few years I have seen ample evidence of people growing a number of heirloom varieties in the same location. We will use beans as an example. Someone obtains their great-grandmother's family heirloom bean which has been in the family for over one-hundred years. Come spring, they plant it in a garden along with a row of blue lakes and a row of half-runners.

Now you have the potential for cross-pollination between these three varieties. You may be the only source of your great-grandmother's family heirloom; And your seed is crossed, the original true-to-type variety is lost forever.

Each year we are faced with the loss of ever greater numbers of heirloom varieties, making proper seed saving techniques all the more important.

If a person is a member of a large organization such as Seed Saver's Exchange and they are growing a large number of beans in the same location and reoffering those seeds through the catalog, then they are passing contaminated seeds on to others who in turn will grow these seeds and offer them to others the following season.

As stewards of these invaluable genetic treasures, we owe it to future generations to pass these varieties on in as pure a state as we found them.

To do otherwise would be something like rewriting history books to suit ourselves.
One exception to this is the fact that a number of varieties which have been handed down over the years contain several variations within the variety. Example of this are to be seen in the Cherokee Cornfield Bean which contains a number of different types, Civil War Butterbean with three distinct colors, and a cornfield type which I have showing at least twelve different seed coat colorations and mottling. These too, though, should be passed on preserving the characteristics that they have shown over the years.

Here are a few guidelines for maintaining seed purity. Grow only one of each variety that you have in a given area. For example, grow one bean, one tomato, one corn, one lima, ect. Isolation distances vary depending on what is being grown. For commercial seed production, corn and limas are isolated by at least one mile. If you live on a farm or large piece of property, you can isolate varieties by growing them in several locations which will allow you to grow more than one bean, for example. Make sure that each grow-out is isolated by at least two hundred feet. If you have several varieties but limited space, grow only one variety every season, that way if you have three beans, you will have three complete grow-outs in three years.

One method that I use is growing my seed collection in different locations which includes borrowed space from neighbors, farmers, and an ecology garden at one of our high schools here in Knoxville.

Practicing these simple procedures will help to insure that our heirloom varieties will be passed on to future generations as well as conserving genetic resources.