It's Thursday morning, the air is crisp - 52 degrees - and Audrey Gillespie, Margaret Hunter, Peg Fitzhenry, and Donna Cole are exercising their annual rite of spring: a daylong trek to the Amish and Mennonite plant nurseries that straddle the Lancaster and Chester County line.

The itinerary, long familiar to serious gardeners in the region, but virtually unknown to everyone else, is meticulously plotted in advance. It would take almost eight hours and 124 miles to complete, and would include nine stops - eight greenhouses and farm markets that sell plants, with a quick lunch at a Pennsylvania Dutch eatery in Blue Ball, where hamburgers cost $2.35 and lettuce-and-tomato sandwiches a nickel more.

The ladies have made this plant pilgrimage for five years now. Nothing gets the juices going in spring like the promise of great plants, good prices, and a day's adventure.

"I always take a day off and go by myself. My husband and kids would be bored to death," says Cole, a payroll supervisor who is already planning a second plant-buying trip, regardless of how much she spends today.

Cole and her pals, members of the Maple Glen Garden Club in Upper Dublin, typically travel on a weekday to avoid the weekend crowds. And always before Mother's Day, the traditional start of planting season in the Philadelphia area.

The group meets at 9 a.m. at Gillespie's house in Fort Washington, where they peel off in two cars whose newly emptied trunks will be stuffed with plants by day's end.

They carry wish lists, credit cards, and cash for the places that don't take plastic. And believe it or not, as the cars head west on the Pennsylvania Turnpike, they talk excitedly about the garden club's own plant sale, only two days hence.

Of course, they plan to shop there, too. They've priced the plants ridiculously low, perennials for only $2! Resistance is futile.

Which is pretty much the backstory for today and the impetus for jokes about "PBA," or Plant Buyers Anonymous, which is not a real support group, but might as well be at this time of year.

Gillespie, 58, a retired financial analyst and software engineer, gets things rolling. "I'm obsessed with tibouchina, the Brazilian princess flower," she confesses.

"Gives you something to look for," replies a simpatico Hunter, 70, who grew up on a Kansas farm, lives two blocks from Gillespie, and serves as club president.

Fitzhenry, 70, enjoys "playing with color" in her Ambler garden, which may explain why her shopping cart is replete with bright begonias, coleus, dahlias, and petunias.

Cole, the most exuberant of the group and, at 42, the youngest, first learned about gardening from her mother, who worked at Burpee, the plant and seed company. Once she married and moved to a house in Horsham, she was hooked.

Now, she walks into a greenhouse and says things like, "I'm in heaven!"

The hour's drive to Exit 298/Morgantown flies by. Before you know it, the ladies have arrived in East Earl Township, Lancaster County.

Amish buggies are clip-clopping past white barns and paddocks filled with cows, sheep, and goats. Young Mennonite women whoosh by on bicycles, while Amish men guide horse-drawn plows through the fields.

The day is warm and breezy now, the sky perfectly blue, the air thick with the smell of manure. Everywhere, wash is drying on the line.

First stop: the Hurst family's Conestoga Nursery, where the garden-club ladies vanish into long rows of trees, shrubs, and perennials tended by men speaking an impenetrable Pennsylvania German.

In just a half-hour, the ladies' carts are loaded up with hellebores and bachelor's buttons, bergenias, creeping phlox, and Solomon's seal, for a collective $60 bill. Gillespie spends nothing, though she lets this slip: "I spent a couple hundred dollars here a few weeks ago."

On to the Horst Farm Market, where you can buy three recycled golf balls for $1 and tomato plants for $1.25. In a scant seven minutes, the ladies scarf up $25 worth of fresh rhubarb, shoofly pie, and cakelike cookies with pink icing from the day-old table, which everyone agrees taste wonderful.

Next comes Black Creek Greenhouses, just down the road, a huge operation owned since 1980 by Harvey Zimmerman. Here, the total tab - the day's highest - is more than $220.

The place is spotless, thanks to Mennonite women in flowered dresses, kitchen aprons, and bonnets, who retrieve hand baskets for customers and answer questions with patience and courtesy.

Philadelphians are quite unused to such politesse, which is also true of the Mennonite proprietor at the day's most interesting stop - Martin's Greenhouse in Narvon.

Gardeners in the know call Marian Martin "Mrs. Martin" and her 30-year-old business "Mrs. Martin's place." It's shorthand for a sweetly quirky woman, 62, who grows for professional horticulturists and home gardeners alike.

Martin welcomes the group with a sprightly tour of her 21/4-acre property, which features greenhouses full of beautiful plants, a miniature garden railway, and sound effects by a nameless rooster who escaped from the barn by breaking a window.

He defies capture, perching just out of reach in a pine tree and crowing at all hours, much to the consternation of Mrs. Martin.

"It's a jungle here," she says amiably, insisting that visitors must see the newly blooming gentians. They are the bluest blue, prompting Martin to observe:

"There's something about nature. You can have all kinds of problems, and it just takes your stresses away."

The haul here: $37.

For lunch, the ladies go for simple grilled cheese, tuna fish, chicken salad, and separate checks, a request often refused in the big city.

But not here. Nothing, it seems, is too much trouble.

And so it goes at several more nurseries and markets, until the car trunks - and backseats - are overflowing.

"We're limited by space or else we'd really have gone crazy," Hunter says.

"I could keep going," adds Cole.

But it's 3:30 p.m., time to head home. The women have spent about $500 on 40 different kinds of plants, sometimes more than one of each, plus fresh vegetables and baked goods.

And Hunter is correct. For these ladies, this doesn't qualify as "going crazy." In fact, later that evening, Gillespie e-mails all: "Had a great time today and bought a lot of plants. But I am still looking for these 2 plants. If you happen to see them locally, could you please let me know where I can find them . . . ?"

Follow the Path

Want to take the same trip as the Maple Glen Garden Club? Here are the eight plant nurseries and farm markets they visited. (The nurseries are closed Sundays and religious holidays. Some are closed Tuesdays, too. Best to call ahead.)

1. Conestoga Nursery, 310 Reading Rd.,

East Earl, Pa. 17519, 717-445-4076. Sells trees, shrubs, perennials.

2. Horst Farm Market, 582 Reading Rd.,

East Earl, Pa. 17519, 717-445-9514. Sells fruit, vegetables, homemade baked goods.

3. Black Creek Greenhouses, 211 E. Black Creek Rd.,

East Earl, Pa. 17519, 717-445-5046. Sells annuals, perennials, bulbs, vegetable plants, hanging baskets.

4. Briar Rose Greenhouses, 1581 Briertown Rd., East Earl, Pa. 17519, 717-354-2167. Sells annuals, perennials, hanging baskets, vegetable plants, tropicals.

5. Martin's Greenhouse, 5489 Division Highway, Narvon, Pa. 17555, 717-354-7546. Sells hellebores, hostas, and other perennials; lettuces; some tropicals.

6. Willow Brook Nursery, 2162 Compass Rd., Honey Brook, Pa., 610-273-7111. Sells annuals, herbs, vegetable and fruit plants, hanging baskets. Cash only.

7. King's Herb Nook, 1060 Compass Rd., Honey Brook, Pa. 19233, 610-273-4583. Sells dried herbs, herb plants, herbal crafts, books, tea, and other products.

8. Route 10 Roadside Market, 941 Compass Rd., Honey Brook, Pa. 19344, 610-273-7793. Sells annuals, fresh produce and fruit, bulk foods, local honey, and other products. Cash only.