2/11/11

Heirloom Seed Misconceptions

Some of my heirloom seeds
The growing popularity of heirloom (aka "open pollinated") vegetables and fruit is great, when considering the massive loss of plant variety and diversity in recent times, as well as the near monopolization - and genetic manipulation - by the seed industry. I sense, however, in casual conversation with fellow home gardeners, that there are misconceptions about saving seeds to grow your own plants.

Consider these scenarios:
  • Your neighbor gives you a cantaloupe, a honeydew and a watermelon, all grown in his garden from heirloom seeds. Can you save and plant the watermelon seeds and end up the same kind in your garden next year? (not likely - this family of vegetables readily cross-pollinates with each other)
  • You buy several tomatoes at a farmer's market which are labelled "heirloom tomatoes." Should you save the seeds from the Cherokee Purple variety you really liked and start your own heirloom tomato plants with them? (no - you don't know the conditions under which the plants were grown)
  • You planted one variety of carrots from heirloom seeds bought by a reputable seed catalog. None of your neighbors grow carrots, so you know you've isolated the variety. You carefully overwinter several carrots and replant for a second season (since they are biennials and don't flower and set seeds until year 2). When you save the seeds from these plants, they should grow the exact same type of carrots again, right? (not necessarily; even with all the precautions you took, the plants could have crossed with Queen Anne's Lace, a wildflower which is actually a wild carrot with a white root - even if they grew 1/4 mile apart!)
  • I've started all my garden plants from purchased heirloom seeds. Does this mean I'll never need to buy seeds again? (maybe, but it depends on many various of growing and seed saving factors)
I'm certainly no expert in saving and growing heirloom seeds, but I've learned enough from books and online literature that I know all the above scenarios send up red flags. If you intend to save seeds for replanting and want to insure you'll get the same plant as the mother plant, I suggest you do your own research. I recommend Suzanne Ashworth's book on seed saving, Seed to Seed, which some consider to be the "bible" of seed saving.

Here's my abridged version of seed saving guidelines…
Generally speaking, plants make flowers, and, if pollinated (i.e. fertilized), the flower will die off and create seeds. Often the seeds are incased in fruit, like many of the vegetables and fruits you are most familiar with: tomatoes, peppers, cucumbers, grapes. With root vegetables like potatoes, carrots, or beets, we are less familiar with the flowers - but all of them do flower, some not until the second year of being in the ground. Leafy vegetables, like lettuce and spinach, are also not known for flowers or fruit, but they too will flower in order to set seeds. With many other vegetables, we eat the "seeds", as with corn, dried beans, and peas. Sometimes we eat the seeds without awareness, like in eggplants, bananas, blueberries. And with watermelon, we spit out the seeds!

Vegetable and fruit plants have various ways of pollinating. With the help of insects, wind, and/or the location of stamen and pistil within one flower (oops, don't want to get too technical!), flowers are fertilized to produce future seeds. Methods of pollination include:
  1. Plants whose pollen from one flower can self-pollinate itself [ex. beans]
  2. Plants whose numerous flowers on the same plant can pollinate each other [ex. tomatoes]
  3. Plants which do best with pollen from another plant within its own variety to fertilize its flowers [ex. blueberries]
  4. Plants which might cross-pollinate with other varieties within its plant family [ex. melons]
  5. Plants which can even cross pollinate with what we think of as weeds [ex. carrots]
Why is this important for saving seeds? These variations mean that planting more than one variety of tomato, melon, or carrot might result in production of seeds not matching the "mother" plant, since they might be pollinated by a "father" from a different variety. The package of some cantaloupe seeds I bought says that for seed saving you should not grow any other cantaloupe, honeydew, watermelon, and others listed within 1/4 mile, since the pollinating bees might travel that distance. So even your close neighbor's garden can affect your seed saving plans. Zucchini squash will cross with yellow crookneck squash, and might also cross with butternut squash, it's "cousin" - same family, different species. On the other extreme, you can grow two types of peas in your garden, separating the two varieties with a row or two of other vegetables, and be fairly insured that seeds saved will grow the same variety. Somewhere in the middle is corn, for which two different heirloom varieties are recommended to be grown 1000 feet apart to insure purity when saving for seed. Books and websites on heirloom seeds often list recommended plant isolation distances for saving seeds successfully, so this info is readily available to you as a gardener.

Some of my heirloom seedlings, in front of a south window
Even if you plant only one variety of tomatoes, and have no neighbor gardens closer than a mile away, you also need to consider the gene pool. Yes, you may be lucky and pick one lone huge tomato from that one plant, save the seeds properly, and grow the same variety next year. Ideally, you want to be sure to select a very healthy plant, and pick many of its best fruit (weak plants produce weak seeds). Even better, plant loads of that variety of tomatoes, take the best fruit from the strongest plants, and mix all your seeds together. This maintains a broader "genetic base" for your seeds (vs. inbreeding), and, over the long run, can even result in fruit better adapted for your specific garden conditions. It's the old "survival of the fittest" thing.

These are just a few of numerous factors to consider when saving heirloom seeds. To do so seriously, you also need to know the best timing for gathering the seeds (watermelon seeds are mature when you are eating the fruit, bean seeds should be left on the plant to dry out, for example), how to best dry seeds, how to store seeds, how and when to plant, etc.

My personal conclusion from all this is that I have converted to starting all my garden seedlings from heirloom seeds purchased from good suppliers, but I am not going to worry about the proper conditions for seed saving. If there comes a time when I can no longer purchase the seeds, I can refer to my library, and isolate my favorite vegetables - as necessary - in order to save seeds for the next growing season. Happy gardening!