Norwich — Memorial Day weekend is traditionally the time for planting, but one group of people grabbing trowels and trays of seedlings Friday morning headed to the low-tide mud flats of the Yantic River rather than any backyard vegetable garden beds.

Workers from Docko Inc. and Thayer’s Marine, along with Norwich Harbor Management Commission Chairman H. Tucker Braddock, raced time and tide Friday morning to plant 2,500 three-squared bulrush seedlings along the mud flats behind Christ Church on lower Washington Street. The area is directly across the east branch of the Yantic River from Thayer’s Marine, which is in the process of installing a 700-foot-long metal bulkhead as part of a larger project to renovate a single-story former mill building along the river as a new boat showroom.

The new bulkhead replaced a decaying, century-old wooden structure, but because the riverbank had become overgrown with brush and trees over time — creating a shelter, shady area for aquatic life — the state Department of Energy and Environmental Protection required Thayer’s Marine to compensate for the loss of riverbank habitat by creating a new natural wetland habitat directly across the river bank.

Keith Neilson, project engineer with contractor Docko Inc., said Thayer purchased 2,500 seedlings from New England Wetland Plants Inc. in Amherst, Mass. He brought the trays to Norwich two weeks ago to allow the plants to sit at Thayer’s Marine and acclimate to the Yantic River climate.

On Friday, Docko employees Kristina Beaulieu and Owen Roberge, Thayer’s Marine employee Pat Emerson, who worked for 35 years at Malerba’s Farm in Norwich and called himself “the best at planting,” and Braddock took direction from wildlife biologist subcontractor Rich Snarski on how and where to plant the bulrushes.

Three-squared bulrushes grow to 2½ to 3 feet tall and thrive in tidal wetlands between the low-tide and high-tide marks, partially submerged at high tide and exposed at low tide, Snarski said. The seedlings planted Friday ranged from 6 inches to a foot tall. The plants will provide habitat for spawning fish, insects and small mammals that live along the riverbank, he said.

Snarski examined the riverbank a couple years ago, when DEEP ordered the wetland restoration, and said the mudflat area across from Thayer’s Marine was ideal for the native North American plants. Snarski, arms coated with mud, instructed the planters to space the plants evenly throughout the roughly 2,500-square-foot area and use remaining seedlings to fill in gaps once the area is covered.

The group started at 8:30 a.m. at very low tide, and finished by 11:30, before they would need to stand in the water. Emerson, however, called the mudflat “quick-mud” and cautioned the others to be careful not to get stuck.

“I’m glad it’s over,” Rich Thayer, owner of Thayer’s Marine, said of satisfying the last requirement of the DEEP permit. He said the permit process started six years ago.

The bulkhead project on the opposite bank is about two-thirds done, with 400 feet of the planned 700-foot metal structure installed. Work on the former mill building is ongoing, he said. “Every day I find something new I want to do with it.”

He couldn’t put a price tag on the total project but said the installed portion of the bulkhead cost about $500,000 already. The building already is providing year-round boat showroom space, a boon to boat sales.

“It’s so helpful for us,” Thayer said of the building. “It has improved our sales immensely. Now we’re 12 months a year instead of eight months. We would want to show the boats, but they were covered with snow.”

c.bessette@theday.com