Lured by the spring sun and goaded by nightmares of conspiring crab grass, gluttonous grub worms, of blades that won't stand up and sod that won't lie down, thousands of weekend warriors trekked to neighborhood garden centers this weekend.

It was the opening engagement of the perennial skirmish of man against suburban lawn.

"I hate it," said Annandale homeowner James E. O'Neill as he bought a sack of grass seed at the Merrifield Garden Center in Fairfax County, adding that he "would seriously question the sanity of anyone who says he" likes it.

O'Neill and other weekend gardeners were lined up 20-deep before the cash registers and scattered throughout the store. Mostly men, mostly middle-aged, holding bags labeled "Estate Lawn Grass Mixture," or, optimistically, "Goodbye Weeds!" they deliberated elbow to elbow over aromatic sacks of insecticide and peat moss, preparing to partake in that rite of spring, the caretaking and cursing of their own carpets of green.

Lawns have long been with us, sprouting up in every civilization, from the Nile to New England, according to Smithsonian ecologist and researcher John Falk. In the United States alone there are an estimated 25 million acres of lawn grass in cultivation. Some of it lines fairways and athletic fields, but it is the suburban lawn, the emerald moat around countless split levels and colonials, that fills the garden shops around the Capital Beltway.

Their lawns may be a lordly 10,000 square feet, or a humble patch of green behind town houses. Either way, said Frank Roediger of Fairfax, as he bought a sack of seed for his 24-by-30 foot back yard. "It's there so I have to deal with it."

John Burkreis, a white-haired, green-jeaned horticulturist at Merrifield, says Washington area residents tend to be baffled because so many are new to the area and ignorant of its soils, worms and weeds. So they rely on "Dr. John," as he calls himself, to pick the proper potion from his extensive collection of chemicals and compost.

"I have 'em following me around like the Pied Piper on weekends, once things really get going," says Buckreis.

The reasons for spending countless hours and hundreds of dollars on a lawn are as many as varieties of grass. For most people, says Buckreis, healthy grass is a matter of pride, and the resigned realization that all the chrysanthemums in Christendom don't matter if the lawn looks like the dark side of the moon.

"The flowers, the shrubs and the trees are the jewelry," he says. "But the lawn--the lawn is the suit. That's really why it's so important. If you're dressed in raggedy-looking blue jeans, all the flowers and all that don't mean a thing. People know that the lawn is what really matters."

"It really does look so attractive," said an Annandale psychiatrist, who asked not to be named as he stood with his wife near the grass seed shelves. "I guess we all grew up with a lawn and we all carry that ideal into adulthood. And it gives you a feeling of renewal."

"We're not about to have any more children of our own," added his wife, "so this is a different way to put down roots, and begin again. And there's a little peer pressure, too. It would be embarrassing to be the only one in the neighborhood with a bad lawn."

The greening of suburbia may be more than peer pressure. Ecologist Falk has tested the terrain preferences of more than a thousand individuals from around the world and has documented an overwhelming preference for savannahs, or grassy land with scattered trees.

Falk believes that preference may be a genetically encoded memory as old as man's evolution in East Africa. "The Serengeti Plain," Falk says, "looks like a big lawn. Man has spent 92 percent of his evolutionary history learning to be a savannah dweller."

In the United States, at least, the savannah is most likely to be a dark green shade of perfectly trimmed Kentucky bluegrass. It hasn't always been that way.

In Europe, as far back as the Middle Ages, and in this country until the turn of the century, the preferred ground cover was a "flowery mead" of varied grasses and wildflowers. Turf scientists working to perfect golf course greens changed that by developing the grasses that Americans now prefer.

"Mud, that's my lawn," said William Froehlich, a 33-year-old Annandale lawyer shopping for lime and fertilizer. "The lawn looks like a beach-front property," he said, the legacy of a family that included four children and two dogs.

Froehlich bought the house last year, but said this year is the year of the lawn. "I'm spending about $50 and giving it about a year to shape up. I hate it, but I refuse to hire one of those lawn services."

Many homeowners have, however. Lawn care is now a $1.5 billion business, according to the editor of a trade publication, and it gets bigger each year as more and more people come to consider the lawn as important an investment as the roof.

Fertilizer and weed therapy aren't for every lawn, of course, no matter who's applying it. "I had a fellow from Georgetown came in here and told me 'name the weed, and I've got it,' " said nurseryman Buckreis. "He wanted to know what to do. 'Blacktop it,' I said. I was just joking.

" 'Thank you,' he says, 'That's all I've been waiting to hear.' And he went and blacktopped it. He really did."