Some Seed Saving Advice, by Lydia S.

Currently I have a couple hundred tomato seeds in my supplies. For the moment, I am focusing on cv. “Raincross Rock” as that is saved seed for a variety I happen to be developing. If I continue to grow and save this variety each year, those few seeds pretty much means that my friends and family (and hopefully many generations into the future) will be assured of a bounty of tomatoes each year. Such is the promise of seed saving!

However, not every plant in every place is a great candidate for seed saving. Plants have rules, too, and while the rules are simple, it is really best to follow them. Thus, this guide.

First of all, it is usually best to save from known varieties that are either heirlooms or open-pollinated. Both of these categories represent stabilized cross-breeds that will tend to breed true. Thus, if you save a “Roma” tomato, the seeds will also show “Roma” characteristics. The difference between these is that heirlooms come with a lineage which is at least 50 years old and sometimes a great deal older than that, while open-pollinated crops are newer, but they are still generally stable and very useful for seed saving. One caution here is to never save from a variety that is labeled “PVP”, or “Plant Variety Protection.” That’s essentially a plant patent. These people have invested thousands of dollars and seeds in protecting their work. Please be mindful of their efforts.

Obviously, a plant grown from vegetative tissue– like potatoes, yacon, oca, garlic, some onions, horseradish, etc.—will be genetically the same as the parent plant and are thus obviously true to type.

Hybrids represent what is essentially an unstable cross. In other words, if you save the seeds of a hybrid pepper, the plants the next year will probably resemble the parent varieties used to make the cross more than they will the plant that was expected. Sometimes this can be useful if trying to make foundation stock from which to breed one’s own variety, but in general it is best avoided. There are a multitude of reasons not to save anything with genetic modifications, either. At the top of that list is that all of those genes are patented and cannot be used in any way, which can lead to civil litigation trouble.

Assuming an heirloom or open-pollinated variety, one needs to know what type of genetic tango the species uses. There are two basic divisions—incrossers and outcrossers.

Incrossers have a variety of pollination mechanisms that ensure a high level of self-pollination. Such species—tomatoes, peppers, lettuce, peas and beans are great examples—usually do not require much isolation from other plants to stay true to type. Ten feet of separation pretty much guarantees purity. Additionally, it is not necessary to save seed from as many individuals. Often, it is possible to save seed from a single specimen without harming its genetic bounty.

Most crops, however, are outcrossers. Outcrossers are a bit pickier. First of all, they like to spread their pollen widely. These crops often use the wind or insects to help spread the pollen between different individuals to assist in the process of maintaining as much genetic diversity as possible. This means that to keep a variety of corn absolutely pure, it might need an isolation distance (distance between varieties) of two miles! This might be a little less depending on the local winds, but generally speaking it is a lot more than the home garden can hope to achieve—particularly if there are neighbors growing a different variety! Also, it is necessary to find a large number of individuals to save seed from. Outcrossers are prone to something called “inbreeding depression” which is essentially a lack of genetic diversity through the generations. Inbreeding depression can cause yield or vigor loss. It is caused by either not saving seed from enough individuals or from trying to save from individuals that are too similar. The number of individuals needed to be saved from varies by species and can range from 6 plants to as many as 200!

Additionally, some crops require special treatments such as fermentation or being saved over the winter so that they will go to seed the next year. In places like southern California , it is relatively easy to vernalize such a crop so it will go to seed, but this can be a bit more challenging in climates with severe winters. The key is that the plant needs to experience cold conditions that are then followed by enough warmth to trigger the reproductive process. For example, in Riverside , California , Zone 10a, chard planted in February often would flower in May of the same year. The increasing warmth of spring was enough to trigger vernalization. To do the same in southern Colorado , the chard would need to be kept alive through the winter either through mulching of roots (cutting back the greens) and season extenders or by harvesting and saving the roots in a cool, humid area.

Here are a few crops for the amateur seed saver to consider.

Beans and Peas

Beans and peas are among the easiest of crops to save, which is one excellent reason that they are a popular component of the “seeds in a can” gardens. If the beans get to harvest stage, it is not hard to get them to the seed saving stage: simply allow some to grow beyond the edible harvest stage until the pod is nearly dried out. At this point the pod will probably be tan or yellow. Shell the beans gently from the pods and allow to dry at room temperature. If they are hard like a dry bean that would be cooked with, then they are ready to be saved. The beans are strong incrossers and require trivial separation between varieties. Simply plant one variety per plot, and separate bean plots with a different vegetable.

Peas are treated almost identically: wait for dry pods, shell, dry at room temperature, and store. Saving enough pods at the end of the season to make up for what was planted that year is a very sustainable practice.


Yes, I’m coming back to tomatoes. Since I am working on my own variety, I do have some experience in saving tomato seed. Tomatoes are pretty much incrossers. To save from multiple varieties, about 10 feet of spacing between varieties is generally needed. An exception is the potato-leaved varieties, which need a bit more spacing. The cross that resulted in the formation of Raincross Rock came from two vines that were practically touching.

I am a proponent of fermenting tomato seed. Some people merely dry it, but others say fermenting helps reduce disease. It is really not that difficult. Save only from tomatoes that are fully ripe red (or whatever the ripe color is). When slicing open fruits to dry them, have a spoon and a glass at the ready. Scoop the seeds and the surrounding tomato gel from the fruits and place that in the glass before slicing the tomato into slices for drying. When there are enough tomatoes for a batch, there usually is a nice glassful of tomato seed goo. Put a paper towel over the glass and set it on top of the refrigerator or somewhere out of the way. Wait several days until a mold has formed. Scoop off the mold (along with seeds embedded in that) and throw it out. Rinse the remaining seeds and dry them. They tend to stick to paper towels; aluminum foil as a surface to dry on works reasonably well. At this point they truly need to be in a dry, wind-free location. Once the seeds are dry, they can be bagged for saving.


Is it possible to discuss tomatoes without discussing basil? There might be a law about that. Basils are outcrossers whose pollen is primarily insect-carried. As a result, a considerable distance (100-150 feet) is needed between varieties to keep them true. Alternatively, try using a screening cover that prevents insects from getting through. Or, just simply save seed from one variety at a time.

To save seed, stop pinching the basil (if doing so) and allow the flowers to form. Once the whole stalk has turned brown, it has died, and the seeds can be harvested. Carefully clip the whole stalk over a plate or bowl. Sometimes the seeds can just be gently tapped from the stalk into the bowl, but often they will need to be gently crushed and then winnow the chaff. The seeds are black, the chaff is brown. Use sieves as much as possible and then gently blow the chaff, which is light, from the heavier seed.


The first thing to remember is that there are multiple species of squashes, although they all belong the genus Curcubita. It is very possible to grow four types of squash and still maintain pure seed saving so long as they are all from different species. That is important as squashes are outcrossers. The pollen is primarily carried between plants by insects, but this can mean separation distances of ½ mile or more.

As an example of accidental crossing, and I doubt one of my friends will ever forget this: I planted what I thought were her zucchini seeds and wound up with this sprawling giant plant that threw white crooknecks. Well, as it turned out, the cross was a good one and we’re anxiously waiting to see if the next generation holds true. But this was entirely an accident, as she had forgotten that she had another Curcubita pepo in her yard. We were lucky that the inadvertent cross was more serendipity than disaster!

Therefore, be very careful which species being planted if the intention is to save seed. The saving process itself is not hard. Let the squash grow far past harvest time, and then harvest when it is totally ready. It can sit another few weeks. Then cut the squash open. For summer squashes and zucchini, just save the seeds. Of course, for winter squash all that yummy flesh needs cooking and freezing or eating. In either case, rinse the seeds clean of debris and dry them on a towel. Once totally dry, they can be bagged.

In conclusion, hopefully this will inspire responsible seed saving, with an eye towards maintaining the genetic legacy that is indeed the inheritance of the heirloom and open-pollinated varieties. May all gardens grow and prosper!

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