Some garden information is not necessary to know, but it helps in the “Oh, I see” category. This column is in that vein.

I’ve been wondering why, after tucking tomato plants back into their cages, my hands look pink, but when I wash with soap, the soap and suds are green and smell strongly of tomato foliage. Why is that?

Lynn Byczynski, writing in “Growing for Market,” wrote that she learned it is a powdery material that comes from the tiny hairs on leaves, stems and fruit that appear in a microscope like miniature water towers containing glands that release acyl sugars, terpenoids and flavonoids.

Acyl sugars are fats soluble in alcohol, but not in water, presumably released by soap, turning soap and water green. Terpenoids release the green tomato odor, and flavonoids are thought to prevent cancer and cardiovascular disease. Tomato breeders think these tiny hairs protect the plants against insect attacks, foliar diseases, and extreme heat and light.

Breeders think they can use these attributes to develop varieties resistant to early and late blights and other diseases. Some are researching enlisting these features to ward off insect attacks too.

Tomato foliage is quite toxic, so it is seldom bothered by insects other than grasshoppers, flea beetles and tomato hornworms. The latter will strip a plant of foliage.

Tomato branches touching or reaching toward soil may develop tiny knobs that look alarming, even to some market tomato growers. I don’t know whether they’re growths of those tiny hairs or whether they’re pushing the hairs aside, but if left to grow, they’ll develop into additional roots for the plant. Technically, tomatoes are perennials, but in our cold climate, we grow them as annuals. In their native home, they may expand and expand, “walking” with the aid of root-establishing branches.

On another tomato note, consider their “shoulders.” That is, the top of the tomato, around the stem end.

Some tomato varieties genetically have “green shoulders,” and that’s considered a flaw in tomatodom. When the fruit is still green, it shows up best, those with “green shoulders” having a darker green top than the rest of the fruit, those without are uniformly light green.

When ripe, the green shoulders remain somewhat green, sometimes turning brownish when the red color overlays the green.

In the past, breeders have preferentially bred the varieties that bear uniformly green tomatoes, unintentionally omitting the gene that also increases sugar and other flavor enhancers. Elimination of this gene doesn’t entirely explain the flavorlessness of the cannonball-like commercial tomatoes, but it’s part of the reason the best thing one can say about them is that they’re wet in the mouth.

Recent research has revealed the importance of this green shoulders-flavor gene.

Other reasons for their lack of flavor is being picked green and refrigerated.

Some think refrigeration is the major reason supermarket tomatoes are so lacking in flavor.

Breeders allegedly haven’t had much time to mess up cherry tomatoes, so they’re more reliably flavorful, according to a recent article in Science News. They haven’t tasted a cherry tomato called Punta Banda. Ick.

Margaret Lauterbach: melauter@earthlink.net or write to Gardening, The Idaho Statesman, P.O. Box 40, Boise, ID 83707