Information published on saving seeds can often be vague and contradictory. Of course all plants can be a little different, and it’s not often practical to discuss each one in detail. A number of books touch on the subject, and Suzanne Ashworth’s Seed to Seed is one of the best. In this article, I am going to try to give a brief introduction to some of the more important issues on the subject.
The home gardener has to take care that different varieties of the same plant don’t cross pollinate with each other. Exactly what will cross can sometimes be difficult to determine. For example, there are 4 different types of squash, none of which are genetically compatible and will not cross with each other. On the other hand, if you have Queen Ann’s Lace growing wild near your garden, it will easily cross pollinate with carrots you try to save seed from, because it is really a wild carrot.
The Latin name of a plant can often give you a clue. Plants with the same Latin name will almost always cross with one another.
Various techniques can be used to prevent plants from cross pollinating, and one of the easiest is to save seeds from an ‘inbreeding’ plant. Inbreeding plants are self pollinating, and generally don’t cross with neighbouring plants unless either special effort is made to force cross pollination or if insects cross pollinate the plants. Seed savers can usually save seeds from these plants without any special care. Examples of inbreeding plants are beans, peas, wheat and most other grains, tomatoes and peppers. These are some of the easiest plants to save seeds from, and in many cases what you harvest for seed is the same as what you harvest to eat.
Another way of preventing cross pollination is to only plant one of a particular type of plant at a time in your garden. It’s actually possible to plant more than one, as long as you insure that only one of them blooms at a time. For example it’s sometimes possible to grow two varieties of corn, one late and one early, and save seeds from both if they bloom at different times. It’s always possible to grow more than one type, and harvest all but one before any of them bloom.
If plants are separated by a sufficient distance, the pollen is unlikely to be able to travel from one plant to another. If you know what the safe isolation distance is for the particular type of plant you are trying to grow, it’s possible to grow more than one type separated by this distance.
Finally, there are a number of techniques to cage or cover plants to prevent pollen from travelling from one plant to the next, but still grow them side by side. I won’t get into this here.
What happens if plants cross pollinate when you try to save seed? It depends on the plant, but often the results are obvious. Since all plants traits are based on pairs of genes, half from each parent, if two very different plants cross pollinate, the results are likely to be very unique. In this case, you can simply discard the unwanted plant. In some cases, slow genetic contamination can occur over time, but this is less common.
Generally as a home gardener, if you use common sense, are as careful as possible, and accept small amounts of crossing as inevitable, you will be fine. Of course commercial seed producers have to be much more careful.
Beyond inbreeding and outbreeding, there is another classification that is important to seed savers: annuals and biennials. Annuals typically grow through the summer, and produce seed in the fall. Biennials require two complete growing seasons before they produce seed. In areas with hard winters, the plants often need to be dug up and brought inside during the winter. Example of biennials are cabbage and related ‘cole’ plants, celery, parsnips and carrots. Most vegetables are annuals.
While it’s not exactly saving seeds, many heirloom gardeners grow plants that reproduce by root division. Example of this are garlic, shallots, multiplier onions, and so on. Since there is no pollination with these plants, it’s not necessary to worry about genetic material spreading between plants. Because there is always the chance of small genetic variations, the process of roguing described below is very important to keep in mind.
Roguing is a very important issue for seed savers. Basically, this means ensuring you are only selecting seeds from the best plants possible. By selecting seeds from the best growing and most productive plants over a few years, you can develop your own seeds best suited to your own local growing environment.
It’s also important to save seeds from at least a few plants, if possible. This is because there are always small genetic differences from one plant to the next, and saving seeds from more than one plant will help preserve these beneficial differences.
As a rule, you should not save seeds from the same plants you eat from, and there are several reasons for this. Many plants will become inedible after going to seed. Often going to seed means the plants life cycle is complete, and it just dies. Otherwise, if you eat some part of the plant before it goes to seed, like the leaves or the first few seeds the plant produces, the plant has to expend energy replacing these, which means less resources will be available for strong and healthy seed production. If you do save seeds from the same plant you harvest for food, you should first save seeds, then harvest for food later.
Beyond keeping all of these things in mind, saving seeds is just as simple as letting plants first bloom, then collecting seeds from the seed pods that develop.
A future post will explain techniques of storing seeds.
