If anyone thought late August is a quiet time for gardeners, think again. Lousy summer to grow vegetables? Hope springs eternal - it's time to plant fall lettuce, greens and beans.

Fall is friendlier than spring on many newly planted perennials and shrubs, so there's no excuse for not getting that landscaping project done. It's also a crucial time to get out and attack weeds, especially those invasive ones, according to Petie Reed, owner of Perennial Harmony Garden Shop, an organic garden center and landscaping service in Waterford. The goal is to get 'em before they go to seed or store up nutrients for next year's growth.

A few years ago, Reed and some other residents in Pine Grove, a residential community and home of the Pine Grove Spiritualist Camp, volunteered to take on the Japanese Knotweed, a fast-growing invasive that is all over Connecticut roadsides and river banks, on a 100-foot stretch of Niantic River bank.

There's a protocol for getting rid of Japanese Knotweed. It involves cutting back the plant three to five times during the growing season, ideally before it flowers, before it goes to seed and, most important, before fall.

"It's imperative that we cut it down before fall arrives," Reed says. "That's because the plant is storing up all of its food and nutrients, moving them from the leaves to the roots. If we cut it down before that happens, there's a better chance that the plant won't survive the winter."

But don't just go out and weed whack it or spray on the glyphosate, a non-selective, broad spectrum herbicide that knocks back everything vegetative that it touches (except for crops that have been genetically engineered to tolerate it, but that's a different story).

"If you don't collect all of the cuttings, or spray on the weed killer, you could actually help spread the knotweed, because the cuttings will resprout, so make sure to bag the cuttings and send them to the incinerator, definitely not the compost pile," she cautions. "Despite the weed killer, its roots stay alive and regrow."

It's very easy to identify Japanese Knotweed after the first frost - just look for the big swathes of dead, brown leaves. By then, it's too late to get a jump on this year's growth.

This New London County clean-up has received front-page billing on the Connecticut Invasive Plant Working Group's (CIPWG's) calendar of upcoming events. The state-wide group of volunteers, from state agencies and UConn to land trusts and individuals, is a clearinghouse of invasive plant information.

Volunteers are welcome to join the clean-ups; the next ones are planned for Friday, Aug. 23, Sunday, Aug. 25, and Thursday, Sept. 5, from 9:30 to 11 a.m. These are rain or shine events, unless there are thunderstorms. For more information, see pinegroveniantic.org or contact Reed at (860) 961-4439 or perennialharmony@msn.com.

Patience and persistence pays off. Reed says that in less than three years, the volunteers have almost eradicated the Japanese Knotweed in this one section and the native grasses have come back. They also plan to plant some native shrubs or grasses to help take back the bank.

"When you clear the invasive plants, you also need to repopulate with the native species you want, so they have a chance to get established," she says.

Two other local cleanups are listed on the CIPWG calendar: Avalonia Land Conservancy welcomes volunteers on Sunday, Sept. 1, from 11 a.m. to 6 p.m. to help tackle garlic mustard, privet, Japanese barberry, winged euonymus and wineberry. For details, contact Joellen Anderson at janderson_alc@yahoo.com.

There's also a Nov. 1 bittersweet clearing of Northern Haley Farm State Park, sponsored by Groton Open Space Association. See www.cipwg.uconn.edu for full listings and contact information.

Helping out with an invasive weed cleanup is a good way to learn how to identify and combat the plants, as well as the native species they are crowding out.

Listen to Petie Reed and Abby Stokes on Suzanne's "CT Outdoors" radio show on Tuesday, Aug. 20, from 12:30 to 1 p.m., on WLIS 1420 AM or WMRD 1150 or streaming online at www.wliswmrd.net. Listen anytime from the On Demand archives on the website.