PORTLAND – Wedged between the calm waters of Back Cove and the near-constant roar of Interstate 295, there’s an unexpected oasis of natural beauty and a learning opportunity for experienced and wanna-be gardeners alike.

Established over the past two years, the YardScaping Gardens at Back Cove showcase nearly 2,000 trees, shrubs and perennials that can help Maine gardeners reduce water use and reliance on fertilizers and pesticides.

“With a garden like this, you don’t need to have those chemicals around your home or running into our waterways,” said Gary Fish, coordinator of the Maine YardScaping Partnership and manager of pesticide programs at the Maine Board of Pesticides Control.

On Tuesday, the partnership will celebrate the grand opening of the state’s first Earth-friendly demonstration gardens that are safe and beneficial to people, pets and wildlife.

Special events are planned from noon to 2 p.m., including free garden tours and instructional presentations. The partnership has more than 30 members, including state agencies, environmental groups and garden centers across the state.

Fish and several volunteer master gardeners were at the Back Cove gardens Friday, weeding, spreading mulch and otherwise getting them ready for Tuesday’s debut.

The gardens spread across 2.5 acres of city-owned land off Preble Street Extension, beside soccer fields and the Back Cove recreational trail. Walkers and joggers regularly pass through the gardens and note their enjoyment of the various plantings.

“It’s beautiful,” a woman called out as she jogged by Fish on Friday. “Everything looks great!”

Fish took the compliment in stride. “We hear it all the time,” he said.

The gardens feature a few permanent signs that explain the benefits of sustainable gardening and highlight several varieties of disease-, pest- and drought-resistant perennials, shrubs and trees. A more detailed list, map and growing tips are available on Maine’s sustainable gardening website, www.yardscaping.org.

There are native lowbush blueberries and pitch pines, wine-hued black lace elderberry shrubs that provide excellent shelter for wildlife, disease-resistant gold flame spirea, and spikey mounds of drought-tolerant blue fescue.

The gardens are designed for various landscapes, from urban to suburban to rural meadows. They also bloom spring through fall. Now, pink flowers are popping on bigroot geraniums, yellow petals dapple the buttercup potentilla and purple spires rise from Walker’s Low catmint. Purple coneflowers and black-eyed Susans will follow in summer, and autumn joy sedum will bloom red in early fall.

Even experienced gardeners may see something new. There’s a lovely cluster of young river birch trees — native to the Ohio River valley — which Fish recommends to Mainers seeking a heartier, insect- and disease-resistant alternative to white birch. There are lush black tupelo trees — native to but rare in Maine — which Fish recommends as strong, slow-growing and largely trouble-free.

The gardens were funded by a $34,000 federal environmental grant, a $10,000 grant from the Davis Conservation Foundation in Yarmouth and about $20,000 in donations from various garden clubs and businesses, Fish said. With the addition of free labor, donated plants and growing time, the gardens are worth as much as $500,000 today, he said.

The gardens were developed and are maintained by about a dozen volunteer master gardeners, most of them trained through the University of Maine Cooperative Extension in Falmouth.

Nicki Griffin, a semi-retired Portland resident, works in the gardens two or three days each week.

“People are so relaxed and get so much pleasure when they walk through the gardens,” Griffin said. “They stop and talk and ask questions, and I’m glad to share what I know.”

The gardens have already won awards from the Friends of Casco Bay and the International Society of Arboriculture. The goal is to develop a nonprofit organization to manage the gardens in the future.

Fish plans to produce an online video tour of the gardens, to be posted on the yardscaping website this fall, that visitors can download to their smartphones. He also hopes to develop similar demonstration gardens elsewhere in Maine.

Built on filled land next to one of the state’s busiest highways, the YardScaping Gardens at Back Cove thrive as a testament to hard work, unconditional love and patience. It’s a powerful example for gardeners waging the endless battle against weeds, disease and insects.

“You just have to relax and lower the bar,” Fish said. “Don’t stress out over your yard too much. It’s OK to have a few weeds, and you don’t have to haul out pesticides the moment you see a bug.”

Staff Writer Kelley Bouchard can be contacted at 791-6328 or at:

kbouchard@pressherald.com