A couple of years ago, I was lamenting to a neighbor about an invasive patch of bamboo. “Cut the stalks back on the full moon in August,” he said. “That’ll kill ’em. It works with alders.” I didn’t know if the advice had any scientific basis, but desperate to rid myself of the noxious weed, I was willing to try the suggestion of my trusted and knowledgeable gardening friend.

If you know about bamboo, you know that its zest for living is unrivaled, and, true to form, mine came back in September. But it made me wonder if the treatment would work on alders or anything less vivacious than bamboo. If you’re able to “kill back” something in August, isn’t it more likely that you’re simply inducing a premature dormancy, I pondered. Perhaps cutting a perennial or woody plant back to the ground that late in the growing season is essentially a way of bringing on the effects of a killing frost.

Science and folklore sometimes clash, unfortunately. One can be trained to be scientifically minded and still gravitate to the teachings of folklore. I tend to think that folklore is formed not through superstition but through observation. It’s a primitive sort of science, you could say.

The moon is perhaps the greatest source of gardening lore. Years ago, a reader wrote to ask about the phases of the moon and what effect they had on gardening.

“When you ‘plant by the moon’ and ‘harvest by the moon’ do you plant and harvest on the day of the full moon or sometime before or after it?” he asked.

Well, that question isn’t easily answered, you see, because it all depends on the crops in question. Some folks say plants that bear produce above ground should be planted between the new and full moon; root crops should be planted during the waning moon – from the full moon to the new moon. Some people say that if the full moon is in late May or early June, you should hold off on setting out tender seedlings because there might be a hard frost the night of the full moon, or, more likely, in the early morning hours.

In “Green Thumb Wisdom,” Joe and Katy Abraham write: “One sure way to be ridiculed by scientists is to hint at a relationship between the moon and any natural phenomenon. This reaction is strong and long-standing. You might recall that when Johannes Kepler suggested that ocean tides were influenced by the moon, Galileo said he was sorry to hear that such a brilliant man should be so stupid.”

In fact, according to the Abrahams, tests conducted in Germany showed that full-moon plantings were said to yield 50 to 60 percent more than new-moon sowings. This scientific explanation of the benefits of planting by the moon may be due to the fact that tides occur in all bodies of water on the earth’s surface, the Abrahams report. Tides may not be noticeable in small bodies of water, but hydrological movement due to changing gravitational force on the full moon may be great enough, even within the soil profile, to cause moisture to be made more available to plants.

So planting by the moon may well have some benefit. As for harvesting by the moon, I don’t know about you, but I harvest when things are ready. In fact, sometimes my daughters and I don’t even wait until they’re ready. If that first, slightly red cherry tomato or immature green bean proves too tempting, after months of enduring grocery store produce, we just pluck and savor it!

For most crops, however, we harvest when the fruit or root is fully mature. Or we harvest before the danger of a frost – a light frost for the peppers and tomatoes and such, and a hard frost for the pumpkins and squash – is upon us.

Truthfully, aside from bits of scientific validation, I really couldn’t say from any prolonged practical experience if, indeed, the moon has any effect on the plants we grow. I do know that I treasure the lore of those that came before me. I don’t care that the bamboo came back after I hacked away at it under the full moon. I do deeply care, however, that a great and experienced gardener imparted that morsel of gardening lore to me.

Lore comes from people before us who perhaps had a greater connection to the earth and natural things. They didn’t have the validation of science to prove their every move. Their success may have been determined more by their appreciation, observation and knowledge of cyclic rhythms, and their hope, perseverance and faith. Those qualities, whether full or masked like the moon, are eternal.

Diana George Chapin is the NEWS garden columnist. Send horticulture questions to Gardening Questions, RR1, Box 2120, Montville 04941, or e-mail them to dianagc@ctel.net. Selected questions will be answered in future columns. Include name, address and telephone number.