Before Martha Buckner plants her back-yard vegetable garden, she will consult the chart in “The Old Farmer’s Almanac” showing the best planting dates.

“In the almanac, it tells you what to plant and the dates to plant them,” says Buckner, who lives in Harrodsburg, Ky. “It’s always worked for me.”

Traditional gardeners like Buckner think the phases of the moon exercise a crucial influence on how plants grow.

“My parents were believers, and my grandmother always planted by the moon,” Buckner says.

Planting by the moon works like this: Every 28 days, the moon goes through four phases — new moon, first quarter, full moon, and fourth quarter or dark of the moon.

In the first two phases, as the moon gets larger in the sky, the moon is said to be waxing. As it goes from a full moon back to a new moon, it is waning.

“As the moon is waxing, its gravitational pull on the oceans is the greatest. The pull affects not just the tides, but everything with water in it,” says John Maruskin, adult services librarian at the Clark County (Ky.) Library. He taught classes at the library earlier this year on gardening by the phases of the moon.

When the moon is waxing, you plant above-ground crops. In the first quarter, plant leafy vegetables such as lettuce and spinach, which have their seeds outside the plant. In the second quarter, plant vining crops that produce seeds inside the fruit, including cucumbers, melons and gourds. Root vegetables, including potatoes and carrots, are planted in the third quarter, when the moon is waning.

“The water is being drawn down into the earth. That helps root structure,” Maruskin says.

In the fourth quarter, “Let your crops rest, but take care of yard work,” he says.

If you want to get rid of weeds, pull them when the moon is waning, because the weeds are weaker.

“There’s not as much life going into them,” Maruskin says.

Ancient astrologers thought that each sign of the zodiac governed a specific part of the body. So they tracked when the moon passed through each sign. The signs start at the head (Aries) and work their way down to the feet (Pisces). Four signs were thought to be especially fertile: breast (Cancer), neck (Taurus), loin (Scorpio) and feet (Pisces).

When gardening by the zodiac, people plant beans when the sign is in the arms, and tomatoes when the sign is in the breast. The ideal time for Buckner to plant peas is April 29 and 30, when the moon is on the rise and the zodiac sign is in the breast.

She has everything ready to plant, but the ground has been too wet.

So what if you miss the perfect date for planting?

“As long as you get close, it’s OK,” she says.

There’s nothing mystical or magical about planting by the moon or signs of the zodiac, Maruskin said. It just combines natural forces with gardening. It just makes a good garden better and increases your yield. You still have to water, weed, fertilize and pay attention to frost dates.

Agricultural almanacs, including “The Old Farmer’s Almanac” or “John Baer’s Sons Agricultural Almanac,” include lots of info about the moon and the zodiac.

“If you look at agricultural data, I think you’ll find there is some correlation between how plants perform and natural phenomenon like the phases of the moon,” says Mark Reese, a retired Scott County, Ky., cooperative extension agent.

Farmers have all kinds of stories about their success when planting in the correct phase of the moon or zodiac sign.

Loyd Smith in Burkesville, Ky., said that one year, he planted two patches of corn. Opal Watson, who ran the country store down the road, told Smith that the first crop was planted under a particularly good sign and would get taller.

“It sure did. It got about three feet taller,” Smith says. That convinced him.

“There’s bound to be a little something to it.”

At a class Maruskin taught this spring in Flemingsburg, Ky., a woman told him that she planted geranium seeds under the right zodiac sign and in the correct phase of the moon, and the seeds sprouted in two days.

“I guess you could say I’m a believer in planting by the moon,” Maruskin says. “I’m not dogmatic about it. My garden does the best when I get out there and work in it.”