How many hours have you spent picking up pine cones in your yard or garden? Probably too many to suit. But one type of pine has cones so rarely that this fall, cones on the ground signal the start of an unusual new crop of valuable trees.

"Longleaf pines produce a good crop of cones only about every seven to 10 years," said Dave Moorhead, a forest regeneration specialist with the University of Georgia Extension Service.

"This year's crop could be as much as three to five times better than the 1987 crop," he said. "That will make it the best in decades."

Longleaf pines are prized for their needles and timber. The needles provide an excellent mulch around flower beds or shrubs. The straight, knot- free timber is often used for poles or high quality lumber.

Moorhead figures well-managed longleaf pines in a good site can be worth up to 20 percent more than other pines.

"About 65 percent of a longleaf pine stand will go to poles," he said. Slash or loblolly pines can grow to pole stature, but much more rarely.

But the longleaf pine supply has dwindled. These premium products are harder to find.

About 100 years ago, Moorhead said, longleaf pines covered nearly 60 million acres. But since then, their area has declined to about 5 million acres. As landowners cut their longleaf pines for their premium wood, they didn't always replant the land to longleaf pines.

"Slash and loblolly pines grow much more quickly and make a good seed crop nearly every year," Moorhead said. As longleaf pines were cut, slash and loblolly pines slowly took over the land.

Farmers or landowners with these pines can help regenerate the species, Moorhead said. "Identify which trees in the stand are longleaf. Then pick out about 20 to keep for their cones."

Clearing other trees and brush helps ensure that only longleaf cones release their seeds into the area. They can also grow without other trees competing for sunlight, water and nutrients.

Seed collectors may approach people who own stands of longleaf pines. The collectors harvest cones from select trees before they open and release their seeds.

Nurseries often buy the cones and plant the seeds. Longleaf pines can grow well in nurseries to be transplanted in land far away from the original trees.

In September and October, the pine cones open and drop their seeds. But Moorhead said people must start preparing now if they choose to regenerate the trees on their land.

"This may be our best chance for another five or more years to increase the number of longleaf pines in our area," he said. "So landowners need to act quickly to prepare for this opportunity."