You hear a lot about heirloom seeds these days. They're touted as everything from a way of honoring our country's agricultural heritage to a safe alternative to genetically altered food crops. Many were brought here by immigrants from all over the world, and handed down from generation to generation.
The fact of the matter is that there isn't any official definition of an heirloom. But there are some things they all have in common.
●Heirloom vegetables are always open-pollinated. That means they can be saved from year to year, and their seeds will breed a true, exact replica of the parent plant. Once you get a hold of an heirloom vegetable, you should never have to buy seeds for it again.
●Some breeders consider an heirloom variety to be one that is more than a century old, but the more commonly accepted definition is that plants are heirlooms if they are more than 50 years old, and handed down through families. Many of these heirlooms originated as cross-pollinated varieties developed on the farm. The seeds were saved and grown for generations. Open-pollinated varieties developed by seed companies before World War II are considered "commercial heirlooms."
●When a breeder uses two heirloom varieties, or an heirloom and a hybrid to develop desirable traits, the offspring is considered a hybrid. Often, seeds from such a mix will produce "throwbacks" that could express any of the traits from any of the parent plants from which it was bred. But if the hybrid breeds its desired traits consistently true for five years, it's considered "de-hybridized" and becomes its own open-pollinated variety.
If you plan on growing heirloom vegetables, use the opportunity to save their valuable, non-hybridized seeds. To do this you should design and plant your garden with a focus on pollination. Many species, such as lettuce, beans, peas and peppers, are monecious or self-pollinating: male and female structures are present on the same plant.
Cross-pollinating or dioecious species, such as onions, cucumbers, spinach, squash, beets and turnips, rely on wind or insects like bees to carry pollen from male plants to female plants in order to set fruit.
No matter what species you're growing, to prevent cross-breeding and risk getting a new hybrid from the seeds, grow only one variety or species of vegetable at a time; or keep at least 10 feet or more between plants of different varieties. The farther away the better, but even still, there's no guarantee that wind or insects won't cross-pollinate your target plants.
If you really want to get involved in a hands-on way, hand-pollinate the flowers using a soft, tiny camel's-hair artist's brush. It's an easy and fun process and a great project to get the kids involved.
Using the soft bristles from the brush, simply collect pollen from the anthers of the male plant. You'll know you're successful because you can easily see the pollen on the brush. Then lightly paint it onto the stigma of the female flower. An Internet search of "parts of a flower" will make it easy to identify. The final step is to gently tie the flower closed, as with squash, or cover with a small paper sack over the pollinated flowers to keep other pollen away.
When harvest time comes, choose the healthiest and most productive plants in your garden and let their fruits over-ripen on the plant. Bring the fruits inside and remove the seeds, allowing them to dry thoroughly on paper towels or coffee filters. Put the dried seeds in a tightly closed glass jar, like a canning jar with a sealable top, and store them in a cool, dry place out of the light.
A silica jell packet in each jar will help keep out moisture; storing seeds in the refrigerator's less-humid salad-crisper section also will help with longevity. Most stored seeds are viable from three to five years; onions, corn and spinach only last for one year. The bottom line is that the sooner you use them, the better chance of germination.
The International Seed Saving Institute has a world-class Web site packed with information about growing and saving seeds. Check it out at seedsave.org.
Joe Lamp'l, host of Growing a Greener World on PBS, is a Master Gardener and author. For more information visit joegardener.com.