Hoping to save what's left of Maryland's dwindling wild ginseng population, the state has banned collection of the sought-after herb on all state-owned lands.

Worried that remaining patches of the slow-growing plant are being stripped from Western Maryland forests by pickers hoping to cash in on its reputed health benefits, the Department of Natural Resources announced this week that harvest would no longer be permitted in state forests or in wildlife management areas. Picking ginseng already was prohibited in state parks.

"Frankly, I think everybody had been expecting it," Jonathan A. McKnight, associate director of the state Wildlife and Heritage Service, said of the announcement. Reported commercial harvests of wild ginseng have declined over the years even as the price the plant fetches has soared, he said. "Maryland is one of the last free-for-all states."

McKnight had said months ago that ginseng collection was going to be banned on public lands this year. But he said the department issued a statement now to alert those who might be preparing for the opening of ginseng collection season, which runs from Sept. 1 through Dec. 1. Harvesting is still allowed on private land.

The move came after a recent survey found that the plant, which once grew across much of the state, including in Baltimore and Harford counties, has nearly vanished from all but Allegany and Garrett. Remaining patches have shrunk in size and thinned out.

"Humans went in and cleared out the majority, then deer have basically gone in and taken out the remainder," said Christopher F. Puttock, a botanist with the Smithsonian Institution's National Museum of Natural History, who coordinated the survey.

Long used in traditional Chinese medicine, ginseng root is believed to have energy-enhancing and healing properties. Though research has not confirmed most alleged benefits, American ginseng has been exported for centuries, primarily to Asia. Collectors in Maryland have been paid more than $400 per pound of dried roots, according to state officials. On the international market, buyers have reportedly paid $1,000 per pound.

The decline goes beyond Maryland. American ginseng is listed as a conservation concern in 21 of the 34 states in which it's found, according to DNR. Fifteen states prohibit harvest and sale of any wild ginseng, while the rest still allow its harvest and export. Pennsylvania and West Virginia allow commercial harvesting from private property but bar collecting from public lands.

Ginseng roots may still be legally collected in Maryland from mature plants on private lands, but McKnight said he expected closing public lands will put a dent in the wild harvest. He said the department has received some complaints from those who forage for or buy ginseng, but those have been outnumbered by people expressing support for conserving the plant.

More than 300 registered collectors reported harvesting just 142 pounds in 2011, according to state records. Nearly 400 pounds of cultivated ginseng were reported sold from the state in the same year, but prices on those roots are generally lower because they're believed to be less potent.

Puttock said banning collection from all state lands "is about as good as we can hope for right now." Maryland's ginseng population hasn't yet dwindled to the point where harvest can be banned on private land under state regulations.

But Puttock said he was worried that the ban might not do much to preserve remaining patches, and that the DNR lacks the personnel to keep pickers from poaching plants. McKnight disagreed, saying he believed most collectors would honor the ban.

Even if poaching is limited, Puttock said, many surviving patches are at risk of being wiped out by browsing deer. He suggested Maryland put fences around them to keep animals and perhaps even people out, and also try restoring the plants in those counties where it once grew.

tim.wheeler@baltsun.com