Thursday, July 31, 2014

Isolation techniques

I walked into a nursery a few blocks from my home and talked to the lady who orders the seeds. She said that heirloom plants were a fad and would fade out in a few years.

I said "Not for me."

There are a number of reasons that people buy heirloom seeds and plants. They are generally a bit more expensive, but they are GMO free (so far), have more variety, and you can save seeds with the assurance that you'll get the same thing next year.

Or...not quite.

If you plant two heirloom varieties of squash close together you might get a hybrid the next year. A pumpsquash maybe, or a waterlope. :) Just kidding.

While tomatoes and peppers, peas and beans, are generally not pollinated by insects (they're self-fertile and most blossoms pollinate themselves) there is still a possibility of a mixture.

There are a number of ways to make sure you get the same variety, mostly determined by the way the particular plant is pollinated.

The simplest is distance. Do not plant wheat, for example, within half a mile of any other strain of wheat. They will mix. Corn is also wind pollinated but the pollen is heavier--plant different varieties of corn about fifty feet apart.

The second option, which relies on the experience of the gardener, is to plant different varieties at different times. This might be as simple as planting each variety in an alternate year, or it might mean planting them a month or two apart. It depends on how long the flowering season is for each variety and how long it takes the seeds to mature. This won't work for some types of plants.

The third, and the one I prefer for most things, is isolation. From a seed bag (scraps of gauze with yarn woven around the outside to make a drawstring bag) to a tent over an entire plant, isolation makes sure that only you can get to the blossoms to pollinate them. Done with a paintbrush, a q-tip, or some other similar item, isolation is the only way to completely verify that you're getting the pollination you want.

It's a learning curve. If you accidentally end up with something unintended, try again next year. That's part of why I always plant only a small portion of the seeds in any one year. I always have something left over from the last batch so I can start over if necessary.

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