When I was growing up, people had to pick the seeds from watermelons while they were eating them. Now we have seedless melons. How did they do that?

-- Vic M. Rogue River

Pick the seeds out, Vic? We ate them right with the watermelon flesh and spit the seeds out. It was great sport when we were kids, until mom reminded us we could put an eye out.

Vic, prepare yourself for a short biology lesson from Bob Reynolds, our local watermelon guru and the Master Gardener program director for the Oregon State University Extension.

The seedless technique has been around for more than 50 years, Reynolds says. One hopes it won't take us that long to wade through this information.

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First you treat a normal watermelon plant with a chemical called Colchicine. This will cause the plant to mutate and create plants with double the normal amount of chromosomes.

Next, you cross the mutated plants with normal plants. Their pairing results in the "seedless" variety.

But there's a problem. Most plants abort fruit that has no seeds. So, to continue growing the seedless watermelons, one must plant the seedless variety alongside at least a few seeded plants. Pollen exchange between the two varieties keeps the fruit growing, says Reynolds.

"The viable pollen falls on the seedless plants and provides enough hormone to keep the fruit on the vine," Reynolds says.

Here's an interesting little factoid at no extra charge, Vic: Wild watermelons, from which our domesticated varieties were bred, were divined by none other than Dr. David Livingstone (we presume) to have originated in the Kalahari Desert.

Send questions to "Since You Asked," Mail Tribune Newsroom, P.O. Box 1108, Medford, OR 97501; by fax to 541-776-4376; or by e-mail to youasked@mailtribune.com.