iparian buffers, those vegetated zones next to water bodies, protect our vital fresh water by filtering out potential contaminants such as nitrogen and phosphorus.
So important are riparian buffers that a fledgling niche industry to produce plants appropriate for buffer use is emerging in North Carolina.
“I think I can safely say that riparian plant production’s total economic impact on western North Carolina for all involved sales and services will exceed $2.5 million within the next two to three years,” says Cliff Ruth, N.C. Cooperative Extension associate area agent for commercial horticulture.
Ruth, who’s based in Henderson County, counts about 25 producers in six western North Carolina counties growing riparian buffer plants and three landscaping companies involved with riparian projects.
Part of the demand for more plants was generated by science-based information that proved riparian buffers to be essential to fresh water preservation.
“Buffers are multifunctional,” says Deanna Osmond, Extension leader for the College’s Soil Science Department, “and are critical for reducing sediment, phosphorus and nitrogen, controlling stream temperature and therefore aquatic habitat and wildlife.”
Nitrogen, in various forms and mostly from farm and urban fertilizers, migrates to groundwater and potentially into streams and lakes. Excessive nitrates in drinking water can cause serious illness or death. Buffers can drastically reduce nitrogen’s migration to freshwater streams.
Osmond, a charter Neuse Education Team (NET) member, works with graduate researcher Scott King to determine the best buffer plant types for all three of North Carolina’s geographic regions.
“We really need studies on the effectiveness of riparian buffers in reducing nitrates in groundwater,” King says. “ Although mountain stream quality is generally considered high compared to coastal streams, sensitive mountain watersheds need protection.
“Since no definitive studies on different vegetative types on buffer effectiveness exist,” he says, “we’re studying the effects of buffer vegetation in both the mountains and coastal plain.”
The research’s mountain aspect – establishing a pre-buffer baseline — is being studied on 20 acres of fine sandy loam along McDowell Creek at the Mountain Horticultural Crops Research Station in Fletcher. The station’s soils mirror those commonly found in North Carolina’s mountains.
King and associates recently planted several vegetated buffers at the Fletcher site and installed groundwater wells to monitor for a year during pre-treatment and three years during post-treatment. They’ll compare groundwater nutrient concentrations of elements such as nitrogen and phosphorus before and after they install buffers to evaluate treatment effectiveness.
The treatments include a tall fescue grass buffer, two shrub buffers — one of witch hazel, wild azalea and red chokeberry at 1,000 plants per acre; the other a native vegetation colonization — and a control buffer of rotated corn and winter wheat planted to the creek’s edge.
Researchers will collect groundwater samples monthly from two well nests installed perpendicular to the creek’s flow to compare effects of nutrient removal. They’ll also analyze upstream and downstream wells for chemicals.
Southeast of the research project, near Tuxedo, is Carol Propest’s plant nursery, Culture of the Earth. She opened the nursery two years ago in a mountain “saddle” along a ridge and up a narrow dirt road, virtually in the shade of a now-defunct tobacco barn.
“Carol was wanting to start a nursery, and she was referred to me by another grower,” Ruth says. “She was brand-new, had no experience at all when she started. None. Zip.”
Now Propest grows 15,000 plants in her fields and 3,000 in her greenhouse, including paw paw, sweet and river birch, deciduous rhododendron and winterberry, a deciduous holly.
“Cliff is a motivator and extremely supportive,” she says, citing a substantial recent sale. “His wealth of knowledge and commitment to growers are equally amazing. I wouldn’t be where I am today without him.”
A few miles away in Clear Creek Valley, in view of Bear Wallow Mountain, Ruth works with Linda’s Nursery owner Joel McCraw to set up the site’s drainage. Runoff water flows along a 2 percent grade to a constructed wetland where Ruth planted iris and swamp hibiscus, then through a barrel riser BMP to Clear Creek.
A bit further down the same creek, Ruth was involved with the N.C. Department of Environment and Natural Resources in a seven-acre wetland restoration project within sight of a downstream I-26 overpass bridge. “The land was farmed,” Ruth notes, “but the owner decided to let it go back to natural. They contacted the county agent, and I was a go-between. I just found a local nursery landscaper to bid on the project.”
Planting mostly in March, workers installed 1,200 plants to the acre: trees such as willows and sycamore; and shrubs, including silky dogwood, elderberries, ninebark and viburnum.
Ruth hopes local landscapers will continue to boost their riparian plant production.
“This is a unique market,” he says. “More and more people are specifying they need plants grown within a 100-mile radius or in the same geographic area. With North Carolina’s three distinct eco-regions, potential growers in an area who supply that area could do well.
“But I know only of about six businesses who could compete with enough material for large landscaping projects,” he says. “In general, landscapers don’t operate on that scale, to be able to provide high-volume quickly. About eight growers produce smaller material. I’m working with two Transylvania County growers who are also involved in installation projects. I have three growers definitely propagating riparian plants in small containers in Henderson County, one in McDowell, one in Jackson and one in Graham County.”
Says Eric Caldwell, N.C. Cooperative Extension director for Transylvania County, where Ruth also has projects: “Although riparian areas may often be viewed negatively by property owners due to regulations or just their perceptions, they are significant economic resources, likely more so than adjoining agricultural fields.”
Caldwell, who is a water-quality specialist, is happy to see greenhouses crank up riparian plant production.
“With this kind of work,” he says, “some of our ‘displaced’ workers can supplement their incomes. And with proper management, riparian buffers can accomplish their ecosystem water-quality BMP function as well as provide an economic function. I like 'win-wins.'"