Rhianna Simes waves a hand at the bins of baby plants nodding in the wind of a blustery April day on the Southern Oregon Research and Extension Center grounds near Jacksonville.

Rhianna Simes waves a hand at the bins of baby plants nodding in the wind of a blustery April day on the Southern Oregon Research and Extension Center grounds near Jacksonville.

"One of Master Gardener's concerns is to reduce the impact of synthetic nutrients and toxic chemicals," she says. "Organic gardening helps to do that."

Simes, of Ashland, will be teaching a class on organic gardening at 4 p.m. Saturday afternoon, one of nearly a dozen planned for the weekend that marks the traditional start of the outdoor gardening season in the Rogue Valley.

The Master Gardener Association's 30th annual Spring Fair will take place Saturday and Sunday, May 2 and 3, at the Jackson County Expo Park's Compton Arena, 1 Peninger Road, Central Point. This year's theme is "Let's go green," in which green is an anagram for grow, recycle, educate, economize, now. The theme will be expressed through information booths, educational exhibits and a roster of free classes.

The Master Gardener Association is a nonprofit group with a focus of providing gardening information to the public. The Spring Fair is its main fundraiser.

Simes has been involved with organic gardening since childhood. She also heads the SOREC Master Recycler Program.

Simes shows off Formosa and Rocky Mountain columbine, both native species, creeping Jenny, veronica, digitalis, coastal strawberries and other growing goodies to admiring visitors. The plants were started from seed or cuttings or propagated from gifts from volunteers over the past three months by students as part of a Master Gardener class, she says.

"Everything we've propagated gets sold to support the program," she says.

This year's event will feature a variety of exhibits on sustainable living, such as container and straw gardening — growing vegetables in straw bales — for adults, and worms and germinating seeds for kids. The fair even promises to show folks "a portable, organic insecticide," but nobody is saying what it is ahead of time.

Veteran green thumbs will again be on hand to identify plant diseases and bugs brought in from your yard and garden or just to answer questions. Fairgoers also can bring samples of well water to be tested for nitrates.

While the Master Gardener program stresses the maximum possible use of organic methods where possible, it is not limited to them.

"We understand that sometimes you're burned out at the end of the day and it's just not an option," Simes says.

Gardening books donated by gardeners will be for sale, with the proceeds going to the Oregon State University-Master Gardener scholarship fund, which annually grants a $2,500 scholarship to an Oregon resident majoring in horticulture at OSU.

For many, the plant sale is the heart of the event. Master Gardener class members have again spent the last three months cultivating vegetables, annual and perennial flowers, shrubs and herbs for sale in the Gramma's Garden and Greenhouse booths.

Don't forget to check out the raffle table. Items here also benefit the scholarship fund. And Master Gardeners' Garden Guide will be on sale for $18 (it's usually $20). It's everything you need to know about growing vegetables in the Rogue Valley.

Simes will be encouraging people to mulch their gardens, both for seasonal veggies and for established trees or perennials. If you've heard mulching doesn't work in the Rogue Valley, she says it ain't necessarily so.

"It's about timing," she says. "We don't need it now. That's where cutworms and slugs and snails come from. But do it when your plants are 6 or 8 inches high and the weather is hot. She mulches tomatoes, peppers, potatoes, cucumbers, squash and even flower beds.

"But do so in a sustainable way," she says. "You don't have to buy something that was made some place and shipped in from South America or Southeast Asia."

She recommends shredded leaves, natural textiles and yard trimmings as mulch.

Admission is $2. Children are admitted free. Parking is free. No pets will be allowed.