From Institute for Urban Homesteading October 1 newsletter, by K. Ruby Blume
Seed Saving Lesson #4 (and last) Don’t Try This At Home!
I have been encouraging you to save seed and I won’t stop. But some plants are a challenge at best especially in an urban environment. It is important to understand how these plants are pollinated and what it would take to ensure seed purity so that we don’t attempt it, get it wrong and in doing so pass along seed that won’t grow the plant it is supposed to. If you are saving seed for your personal use–it really doesn’t matter if the seed is pure–save and experiment away.! Indeed many valuable varieties were developed in haphazard outcrossings by home gardeners and small scale farmers. At some point though, they isolated that seed and made it “stable” Here are some crops considered “advanced” in their seed saving requirements.
Corn is wind pollinated. Each silk leads to the embryo of one kernel of corn. the Tassels put out copious pollen to ensure that each silk gets a grain. Isolation distances are up to 2 miles for corn. To ensure purity, the ears must be bagged before the silks come out. The bags are quickly removed, hand pollinated with several tassels and then replaced. To ensure diversity a minimum of 100 plants to work with is suggested.
Carrots readily outcross with their wild relatives such as Queen Anne’s Lace and can revert to a woody unplalatable root in just a few generations. Carrots go to seed in their second year, so seed saving is a long term commitment Like corn carrots need bagging and at least 100i individual plants to ensure good genetic diversity.
Brassicas (broccoli, kale, turnip) are insect pollinated and extremely attractive to bees. They love to cross within their species and with less tasty wild relative such as mustards, radishes and wild cress. To ensure purity the require 1/2 mile isolation distance and/or caging with introduced pollinators. They also need a larger group of plants to ensure good genetic diversity.
Chenopods (chard, beets) The chenopods have tiny, unspectacular flower which produce copious pollen which can travel up to 5 miles on the wind.
They readily outcross with less spectacular wild food plants like lambs quarters and pigweed. Commercial production relies on isolation distances for purity, in the home garden the seed stalks must be bagged with additional cotton batting around the stalk to prevent pollen from escaping!.