[Update: I wrote this post in 2007, and now it’s 2012. I see in my log files suddenly a lot of people are reading this post again, probably because a number of you have posted it to Facebook. That’s great! Welcome to the exciting world of seed saving!
It’s not that what I wrote is wrong or out of date, but now looking back 5 years if I were to write this post today, I would spend more time talking about inbreeding depression. If you are saving seeds from a plant that doesn’t need isolation like peas, beans or lettuce, you also don’t need to worry very much about inbreeding depression. You may also choose not to worry about inbreeding depression if you don’t intend to share your seeds with others, and are just experimenting within your own garden.
If however you do plan to share seeds with others and your plants can cross with other plants then you need to think about both isolating them (like I explain below) AND inbreeding depression — these two always go together. In this case, have a look at a later post I made about this.]
Saving seeds from almost any fruit or vegetable is possible, but some are more difficult than others. Indeed this whole subject can be complicated, and is the point of disagreement between many gardeners. Here are some simple suggestions if you are new to seed saving.
The important thing to remember about saving seeds is you must choose heirloom or open pollinated (OP) plants to save seeds from, or you risk unpredictable results (which isn’t always a bad thing, but probably not the best place to start). Since companies that sell both standard seeds and heirloom/OP seeds are usually prohibited from labelling them as such because of agreements with their suppliers, you must very carefully search for this kind of seed. You generally either have to buy them from a company that specializes in this kind of seed, like some of the ones mentioned on the front page of this blog, or you have to get them from a fellow gardener. Never assume seeds that are not explicitly labelled as open pollinated or heirloom are suitable for seed saving, and even those that are but sold by a company that also sells normal seeds should be considered suspect!
When you save seeds, you should try to save them from more than one of the same kind of plant if possible. This is important for long term viability. If you are just saving seeds for your own garden for the following year, it’s not very important. If the seeds are destined to be shared and grown for many years, the vitality of the seeds will diminish if the breadth of the gene pool is not maintained.
It is also very important to only save seeds from the best plants, so that you preserve the genetic traits from them. You should never save seeds from obviously defective or diseased plants!
Self-pollinating Annuals
Nothing could be easier than these. These are self-pollinating plants that do not require pollen from neighbouring plants and tend not to cross-pollinate with each other. These plants mature and produce seeds in the summer or fall. For these plants all you have to do is save the seeds!
Peas: Just let the plants die off, and gather the seeds from the pods. Since they don’t normally cross-pollinate with each other, you can grow as many varieties of peas next to each other as you want.
Tomatoes: Wild or currant tomatoes can cross pollinate with each other and other neighbouring tomatoes, but normal tomatoes don’t cross pollinate easily so you can generally grow as many of these next to each other as you want. Since there is a small chance of cross pollination, it’s good to avoid letting the plants touch and allow a few meters of space between the plants, if possible. Instructions for saving tomato seeds are here.
Beans: Normal pole or bush type beans do not tend to cross pollinate with each other very much. To be on the safe side, allow a bit of space between different types of beans if possible. Pole varieties are more likely to cross than bush varieties. Soy beans almost never cross. Lima (butter) beans and fava (broad) beans do cross with each other, and are probably not a good place for a beginner to start unless you are just growing one variety. Normal bush/pole beans, Soy Beans and Lima beans are three different species and will not cross with each other. In all cases when saving seeds, just let the plants mature and die off, and gather the seeds.
Peppers: Same as tomatoes, but to save seeds just let the peppers fully mature on the plant then lay the seeds out on a piece of paper to dry for a few days. Be careful of hot peppers! For hot peppers make sure you don’t touch your eyes or nose after handling them, consider wearing rubber gloves, and in any case wash up carefully after you are done.
Pumpkins, Squashes (Courgettes) and related: These are not actually self pollinating, but there is an easy trick to these. There are 4 main species of this kind of plant: Cucurbita Pepo, Cucurbita Moschata, Cucurbita Maxima and Cucurbita Mixta. As long as you don’t grow more than one of each species, they will not cross pollinate with each other. The seeds are usually labelled with the species, and in any case searching on the Internet you can usually determine what it is. To save the seeds, let them fully mature on the plants, then spread the seeds out to dry.
Lettuce: Lettuce does not usually cross pollinate, so you can grow as many different kinds as you want next to each other. Be careful not to save seeds from plants that bolt (or go to seed) prematurely, or you may preserve this genetic trait.
Grains: Grains such as wheat, spelt, barley and so on don’t normally cross pollinate. You can generally grow as many of these next to each other without cross pollinating. Many people don’t understand the potential in growing this kind of plant, and there are many exciting heirloom varieties available!
Biennials
This type of plant is a little more of a challenge to save seeds from, but is still suitable for beginning seed savers. Biennial plants produce seeds in their second growing season, usually in the spring. This type of plant will almost always cross pollinate with similar plants, so you can only grow one variety of each species. In other words one each beet, parsnip, celery root, etc. In fact it is possible to grow as many different varieties within each species, but you must ensure that only one blooms and goes to seed at a time. In areas with a hard winter this sort of plant can be even more of a challenge, because it must be able to survive the winter.
Most people find it easier to transplant all their biennial plants they are saving seeds from to one out of the way place, to make room for the following years garden.
Beet and Swiss Chard: These are both really the same species, only one is grown for the leaves and the other the root. They will cross pollinate with each other. If you grow either of these for eating, just select a few of the best plants, and leave them in the garden to save seeds from.
Parsnips: There are wild parsnips that can cross pollinate with what you grow in your garden, so you must make sure none of these are growing any place nearby. Be sure to give these plants lots of space, because the flower stalk on them is huge. The sap of these plants is very irritating, so avoid contact with the skin.
Celeriac (Celery Root) or Celery: These are the same species, just one grown for the tops and the other the bottom. They will cross pollinate with each other. Celeriac is considerably more winter hardy than celery, but neither will survive a very hard winter.
Parsley: This is very easy to save seeds from. Just insure you only grow one variety of parsley at a time for seed saving purposes.
Turnips: This is a member of the cole family, which includes Cabbages, Brussel Sprouts, Mustard, and so on. They will all cross pollinate with each other, so you can only save seeds from one at a time. Turnips are one of the easiest because the plants are small. Make sure you save from several plants to preserve the gene pool. The seeds will not all mature at the same time, so you will have to collect the seeds slowly over time. The flowers must be insect pollinated, and must receive pollen from a different plant in order to produce seeds.
Plants without Seeds
Some plants do not form seeds and so do not cross pollinate. These are often very easy to grow in your garden, save plant materials from and trade with others.
Garlic: See my earlier post about this.
Perienniel Onions: Grown similar to garlic.
Potatoes
Jerusalem Artichokes: Be careful, these can be very difficult to eradicate from your garden once you start growing them.
Horseradish: See the warning for Jerusalem Artichokes.
There are many other plants in this category.
This is about it for the easiest plants. Of course it’s possible to save seeds from almost any plant that produces them. For more information see Seed to Seed, the excellent book by Suzanne Ashworth.
