Friday, July 22, 2011

Seeds: Making and Saving

I think seed saving is very important. For one thing, It's cheaper. The majority of money I have spent on this garden has been for seeds. (The next-highest expense was the $100 or so we used to put up the fence that separates the vegetable garden from the rest of the yard to keep the dogs out). Granted, I do prefer the interesting heirlooms from seed catalogs, which are more expensive, over the cheaper hybrids on the rack at my local hardware store. Now that I have these heirlooms, however, I can save the seed myself and have enough for myself and to share with others for years to come. There is a lot of good seedsaving information online and in books, but I'll share a quick example for saving tomato seed, since tomatoes are so popular with backyard gardeners.

First, needless to say, you have to have seed to save. That can be tricky. In short-season areas, it may be difficult to get mature seed before frost hits and kills the plants or rain comes and makes the drying seed mold. In hot climates, we have a different problem. High heat and pollen don't go together.

Obviously, some plant pollens like high heat more than others. Peppers and tomatoes have pollen that is viable at higher temperatures than, say, cabbages. But even hot-weather vegetables have their limits.

According to a gardening guide published by Colorado State, "Tomato pollination is temperature dependant. If nighttime temperatures drop below 55 degrees, pollen fails to develop and flowers that open the following morning will not set fruit....If the daytime temperature reaches 90 degrees by 10 a.m., blossoms that opened that morning abort."

When I was harvesting the first of my tomatoes, the ones I was so happy to find with few seeds, I didn't consider the temperatures. We'd been having temperatures veering wildly between periods of cold nights and days in the triple digits while those tomatoes were forming. This resulted in smaller tomatoes with few seeds. Now, our weather has settled to what I will tentatively call "normal" as you can see below.

I am also getting larger and seedier tomatoes, as the flowers are being pollinated more thoroughly. It still seems to hot for beans, as I am seeing many bean flowers yet no bean pods. I am collecting more varieties of cowpeas, including the lovely and reliable yardlong bean, since Vigna unguiculata can flourish in higher temperatures than Phaseolus vulgaris. I will also be trying the drought and heat tolerant tepary bean, Phaseolus acutifolius, next year.
What can be done about it now? I notice that flowers are more likely to set fruits in denser plantings, where I assume the shade and humidity keep the temperatures down. So tighter plant spacing may help. Also, I think rigging up a light shade cover might help.

Anyway, here is how I save tomato seeds. I process seeds in a small batch because I don't need thousands of seeds for next year.

The good news is, tomato plants don't need any special treatment to produce seeds (radish plants, for instance, have to be kept in the ground much longer to allow them time to flower and set seed, and they need to be staked to keep them from falling over. They get big). Nor do you have to do anything special with the fruit. It's already ripe with mature seeds.

The bad news is, tomato seeds are covered in a substance that inhibits sprouting. The plant intends for the tomato to fall off and rot before the seeds sprout. For the most successful germination next season, we should mimic that process.

Start by scooping the seeds out of several ripe tomatoes, into a small container. I use a cup measure. You can use the remainder of the tomatoes for something else. Like salsa. Mmm. Anyway, add a little tap water to the slurry in the container. Just a bit. You want a soupy mixture. Now, you're going to let this mixture ferment to break down the germination inhibitors in the tomato gel around the seeds. Cover the container loosely (I stick mine in an unsealed plastic baggie) and make sure it's labeled with the variety you're saving. Set it someplace you won't forget it. You don't want to forget it.

After a couple of days, the mixture in the container will get moldy. It looks gross. This is why you don't want to forget it and find it next month.

Now, add some more water to the container and swish it around a little. The scuzzy stuff will float, as will any nonviable seed. Mature seed will sink to the bottom. Pour off as much scuzz as you can. Then dump the rest into a fine-mesh strainer and rinse the seeds well under running water.

Then spread the cleaned seed out to dry. I like to use paper plates for this. Label the plate, too, so you don't get the seeds mixed up with some other variety (this may provide one more level of insurance against a significant other throwing the plate away). When the seeds are completely dry, they can be stored. If you're not sure whether they are dry enough, leave them out longer. Improperly dried seeds mold. A fully dried seed should snap if you bend it, but few tomatoes have seeds large enough to bend.

Congratulations, you've just saved yourself at least $2.50 on a pack of tomato seeds next year. More likely, you've saved several packs worth of seeds and now can share them with other gardening friends, exchange them for seeds you don't have on GardenWeb's seed exchange, or even sell them through organizations like Seed Saver's Exchange. Seeds vary in their longevity - onion seed is notoriously shortlived - but tomato seeds can last 5 years or more if you store them somewhere cool and dry. Now you'll never have to worry about your favorite tomato variety being bumped out of production by something trendier.

Don't laugh, it happens.

A note on hybrids: Most gardeners are aware that hybrid varieties don't "breed true" - the offspring will not be the same as the parent plant. Most books and articles add, "so hybrid seed is not worth saving." If you are the inquisitive sort, this is complete bunk. It is true that hybrid plants will not produce identical offspring (although seed companies have been known to label true-breeding, open pollinated seeds "hybrid" to discourage seedsaving and encourage customers to buy new seed every year), hybrid tomato plants will still produce tomato seeds. If you grow out the seeds next year, you will be greeted with several different types of tomatoes. You may like one of these new types better and you can develop your own new variety from that plant. Or one of the types might be very similar to the original tomatoes and you can develop your own open pollinated version of the hybrid tomato. For an excellent explanation of this type of plant breeding, see Carol Deppe's Breed Your Own Vegetable Varieties.

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