Saving Garden Seed

Published: September 1, 2009

As the growing season progresses many gardeners consider whether or not they should save seed from this year's garden to plant next year. There is no doubt that seeds of flowers and vegetables are becoming more expensive. For example, if offered an ounce of gold or an ounce of fibrous-rooted begonia seeds choose the latter (given you have a way of marketing them). A recent check of a popular seed company’s internet site put the value of begonia seed at $43,000 per ounce at the listed price per packet of 150 seeds. Of course the caveat here is that there are two million begonia seeds per ounce making the cost of an individual seed more palatable.

While thriftiness is considered a virtue by most, saving seed might not be the money-saving venture it would appear to be. A majority of the ornamental and vegetable plants we grow in our gardens today are F1 hybrids. They tend to be more vigorous, uniform and productive than their non-hybrid counterparts. F1 hybrids exploit a phenomenon known as “heterosis” or hybrid vigor which occurs when two carefully selected parental lines are crossed to form a hybrid offspring.

Heterosis, however, does not carry over from one generation to the next but must be fixed each generation by remaking the original cross. Therefore seed saved from a hybrid variety will not produce a plant with the same characteristics as the plant that bore it. Progeny of F1 hybrids tend to revert back in form to one of their parents. Genetically, this phenomenon is known as “segregation” and is a manifestation of one of the Laws of Heredity established by Mendel over 150 years ago.

The wisdom of saving seed from openpollinated (non-hybrid) ornamentals and vegetables depends on a number of factors. Species that naturally are cross-pollinated (e.g. watermelon) derive their pollen from a male parent of the same species of unknown identity. Seed saved from an open-pollinated variety of watermelon such as ‘Sugar Baby’ will be “true to type” only if there were no other varieties of watermelon in the immediate area that might have served as a source of pollen. The safe isolation distance for seed collection for species pollinated by honey bees is consider to be one-half mile. For species cross pollinated by wind the safe distance depends on species and local conditions (e.g. topography and vegetation density).

Self-pollinated, non-hybrid species represent the best candidates for saving seed from the garden. Perhaps no better example exists than heirloom tomatoes but certain precautions still must be followed. Since tomatoes are self-pollinated, saving seed from heirloom varieties will result in seeds of the same variety as long as accidental cross-pollination has not occurred. Insects such as the bumble bee and (occasionally) wind can cause cross pollination. Therefore to assure genetic purity producers of heirloom tomato seeds isolate varieties to prevent accidental cross pollination. The same must be done by the home gardener to assure genetic purity.

If the decision has been made to save garden seed then it should be collected from healthy plants. There are several virus diseases that are known to be transmitted through seeds. Clean the seed and try to sort out any that appear to be non-viable. The latter are usually smaller in size and lighter in weight. Cleaned seed should be stored in a cool, dry location. A jar with a tight-fitting lid containing a small amount of silica gel makes a good storage container. Label the jar and place it in a refrigerator or other cool location.