Developing New Varieties

Deppe started breeding her own plants out of necessity. In the case of this heirloom squash variety, the Guatemalan blue banana squash (figure A), there simply weren't any seeds available on the market. "This particular squash is so delicious," says Deppe, "I hate to do without it, but the only way I can have it is to be able to save my own seed." But in order to save her seeds, she has to be sure they're formed, and that's done by good old pollination. "I have to be able to hand pollinate," says Deppe. "I take pollen from these plants and put it on female flowers of this plant in order to get pure seed."

Females have a baby squash underneath (figure E), and they too must be sealed so that the wind or insects don't deposit the pollen of a different variety of squash in the flower. If that did happen, Deppe would still get a crop of Guatemalan blue banana squash, but the seeds for next year would be half Guatemalan and half something else. And remember, she's breeding for purity.

"The pollen is on this structure in the middle (figure F). There's a similar structure in the female flower that is the receptive portion of the female." Deppe removes the top from a female flower, dabs the top of the male flower around the female's stamen; that's the structure in the middle of all the petals (figure G). The pollinated female must be isolated from any other pollen, so Deppe tapes the flower shut again, and marks it with a ribbon indicating date, plant time, and pollination method. In a few days, the flower will fall off and the squash will continue growing. When it's ripe, she'll collect the seeds for future plantings of pure Guatemalan blue banana squash.

There are lots of different plants that can be bred, even corn, which is usually wind pollinated. Deppe wants a cake-grade flour corn that is a beautiful magenta color, so she's breeding her own. "This tassel is releasing pollen right now (figure H). And there's a baby female flower right there with the tassels just coming out." The pollen is on the tassels at the top of the plant. As soon as the tufts of silk appear from the ears of the corn, Deppe gently taps the pollen from the tassels over the silks (figure I). Deppe then covers the silks with an envelope (figure J) to protect it from other pollen. She'll do that for three consecutive days to ensure pollination for the entire ear. She's still fine-tuning this particular breed, but look at some of her crops so far this year (figure K).

For more adventurous gardeners, Deppe suggests trying a wide cross--that is, breeding similar but different species. "Since I don't grow leeks and I want a multiplying leek, I bought a leek in the supermarket and I planted it next to my onion patch (figure L)." Since there aren't any flowers or silks to pollinate, Deppe ties the flowering leek head to the flowering onion head (figure M). Now when the pollinating insects walk from one flowering head to the other, there's a chance she could get a cross. When the flowers dry, she harvests the seeds separately, and plants them in separate flats. Any seedling that looks different from the rest could be an exciting new species. "I don't know what I'll get, but whatever it is, it's bound to be fun."

So why not try your hand at breeding your own cultivar? Not only could it be fun, but you also might wind up with something that is as good or better than what you're already growing. One word of advice however, Deppe says don't plant all your F-1 hybrid seeds in one year. Drought or frost may be rather unforgiving that year and you don't want to lose a whole year's worth of experimentation.