Saturday, 8 September 2012

Saving Vegetable Seeds - Annual Self Pollinators

There's a lot of information out there about saving seeds, much from people a lot more experienced than me at saving seeds. But as I've gotten interested in the subject, I've realized just how much misinformation is out there too, and I thought I'd try to clarify, for myself as much as anyone else, what I have been learning this year about saving seeds. I'm also going to break it up into several posts, because it's a big topic.

It is my plan to start saving a lot of seeds. For one thing, sometimes favourite things just disappear from the seed catalogues, never to be seen again. I remember growing a yellow pole bean called Gold Straw when we had allotment gardens, about 15 years ago and really, really liking it. Can I find it now? Not so much as a whisper of its existance. Also, seeds can get expensive. Individual packets don't usually cost much, but when you multiply them by a garden full, that can be some real money. If you can cut the amount of seeds you need to buy even in half, it will make a real difference. So, I'm going to start by saving seeds from annual vegetables, that is the ones that produce seed in their first year of growth. For obvious reasons, this removes a whole layer of complications and makes them usually the easiest to save seed from. To make it even easier, I'm going to stick with annuals that are also self-pollinating.

Vegetables that can produce seed by self-pollinating - also know as inbreeding plants - do not suffer from inbreeding depression, which can reduce the quality of a strain of seeds in vegetables that require external pollination (outbreeding plants). It is therefore possible to save seeds from a much smaller pool of parents. However, just because plants are USUALLY inbreeding does not mean that they CANNOT oubreed, and care must still be taken to avoid crosses, or at least you must be prepared for the possibility.

Essentially, that means peas, beans, and members of the solanacea family such as tomatoes and peppers.

Eggplants, like tomatoes and peppers are generally self fertile but may cross. Tomatillos will cross with each other, but are generally similar enough to each other that it doesn' matter. Ground cherries, I suspect pretty much the same, and at any rate unless you are a ground cherry breeder you are not too likely to be growing more than one strain. Potatoes are an entire topic on their own, and I will not discuss them here.

The easiest and most financially rewarding seeds to save are for peas and beans. They are generally packed very few to an envelope, as they are large and bulky, and expensive to ship. Furthermore, they are self-fertile - they are actually usually fertilized and the peas and beans ready to develop before the flowers even open. I say usually. Some people say they have a lot of problems with beans crossing, and others say they don't cross. I've had no problem with them crossing in my garden even growing different varieties jammed right up against each other. I suspect it depends very much on your particular situation. My suspicion is that the closer you are to the ancestral home of beans (Central America) the more likely you are to have insects in your garden that are capable of cross-fertilizing them, although I have no proof of this. I think in general we are probably pretty safe around here, but note that I make no guarantees. Peas, on the other hand, are more reliably self-fertile everywhere.

Tomatoes are a plant that a lot of people save seed from, and they are treated very similarly to the related peppers. Like peas and beans, they are annuals, and like them they are self-fertile. Here's where I differ from the common wisdom again... most people think tomatoes don't cross often. My experience is that they DO INDEED cross often enough for it to be a bloody nuisance. I've gotten more crossed tomato seeds than anything else, both from my own seed saving, and from seed companies who should damned well know better. One source says that peppers and tomatoes are 85% self fertile. Other people report crossing rates varying from 5% to 40%! Here are a few useful observations.

Conventional advice is to keep your tomatoes separated by 25 feet. Good luck with that, in most gardens. If you want to save seed, probably the best advice is to bag the blossom with a sheer nylon bag before it opens, and keep the resulting tomato well marked until ripe and seeds can be extracted. There is some good information on tomato seed saving here. Or perhaps even better advice: glue the unopened flowers shut. Then, mark the resulting tomato to save for seed. I really will have to try this.

It is my understanding that tomatoes with blossoms that have a long style (the tube with the stigma at the end, in the middle of the flower) are more likely to be cross pollinated, as are tomatoes with large blossoms. In general, this seems to mean the larger tomatoes. I've had problems with Striped German and Paul Robeson in particular. But it can happen with smaller tomatoes too - I'm growing a plant which ought to be Jaune Flammé this year, but which plainly isn't quite. I'm actually going to save seed from it - in the hopes that it hasn't crossed with anything else and that it's stable- because in fact it's a nice, tasty little red tomato with some of Jaune Flammée's best qualities: early, productive, robust and very long producing. But most of the crossed tomatoes I've grown have been noticeably inferior to their parents. 

Peppers, it is my impression, are even more prone to crossing than tomatoes. Furthermore, if you grow both hot and sweet varieties, you may be in for some unpleasant surprises if you save seed. In particular, sweet peppers from crossed seed may grow to look exactly as they should - but be hot, rather than sweet. So, if you intend to save pepper seeds, even more care to isolate them will be needed, and bagging or otherwise sealing off the flowers from outside pollination is still recommended. The situation is a bit more complicated than that, in that there are 5 species of peppers grown in gardens (although around here, really only 4) and they may or may not cross with each other. Still, the large majority of peppers grown in Canada are members of the capsicum annuum species, and will cross.

As far as the mechanics of seed saving, most of these are also very easy. Allow peas and beans to dry on the plant, but remove them and shell them before the shells split naturally and spill the seed.

Pepper seeds need only be removed from very ripe fruits and dried. Eggplant as well, although for them "very ripe" is a state few gardeners and cooks will ever see. Allow the first eggplant to form to go to seed; it will likely take all season to ripen, until it turns yellowish. Mash the flesh and wash out the seeds - the sinkers are the good ones (This applies to most seeds.) The same technique can be used for tomatillos and ground cherries.

As for tomatoes, there are two ways to go about it.Most people prefer to squeeze or scoop the seeds, with the surrounding gel, from the chosen ripe tomato into a jar of water, which should then be left in the sun to ferment for a week or so. A rather revolting layer of mold will develop on the surface. Add more water, stir up well, then rinse the seeds well in a mesh colander to clean. This fermentation will help kill diseases, but is not strictly necessary. If you do not think you can do it, scoop the seeds out and rinse them. Lay them on a piece of paper towel to dry thoroughly for a week or so, then scrape them off and store them as usual.
You should not save seeds if you have known diseases in your plants, although if you cannot replace the seed any other way, choose the best, least affected fruits you can find to save some seed from. Dry and store them as usual, but soak them in a solution of 1% to 3% hydrogen peroxide for 12 hours before planting. Actually, this brings me to the next point about seed saving, which is selection...


Debbie said...

Hi Ferdzy, I read both posts about saving seeds - it's more complicated than I imagined. One thing I always wondered about is, should the seeds be frozen for a period of time, as in nature, they would freeze on the ground over winter before sprouting in the spring.

Ferdzy said...

No, vegetables are almost always easy, warm germination and stratification (freezing) isn't necessary.

For best storage, they do need to be kept cool, dry and dark. You may store dry seeds in the freezer if you like - that will help them last longer, especially things like onions and lettuce that are not long-lasting seeds to start with. But it isn't a requirement.