Last week Plant WNY (formerly the Western New York State Nursery and Landscape Association) hosted two days of education for professionals and avid gardeners, and I’d like you – the gardening public – to know what the pros are talking about. This year was exceptional for the intensity of focus on certain themes and the seriousness of the topics. It certainly wasn’t all about the pretty flowers.
On Day One, designed for Certified Nursery & Landscape Professional (CNLP) education, two classes addressed the serious problem of stormwater runoff and what landscapers and municipalities can do about it. Stormwater is rain or melted snow that flows over the ground and doesn’t infiltrate the soil, as would normal precipitation.
In urban areas such as Buffalo, storm events were once relatively rare and manageable, and for many decades there was enough green space to take in the water. Then cities sprawled, and soon that water was forced to run over ever-expanding impervious surfaces – parking lots, buildings, roads and sidewalks. (One study nearly two decades ago reported 43,000 square miles of impervious surfaces in the U.S. with about 400 square miles being added every year.)
With increasing frequency in Buffalo, stormwater merges with sewer water, and the combined sewer overflow travels straight to our lake (where drinking water comes from).
Especially in cities like our own, with an aging infrastructure that was built for a much simpler world, structural solutions are nearly impossible. Can you imagine digging up and rebuilding the pipes under the entire city? The alternative to rebuilding is redirecting stormwater and preventing runoff. That’s where plants come in.
Nina Bassuk, of the Cornell University Urban Horticulture Institute, presented “Woody Shrubs for Stormwater Retention,” based on research showing what shrubs will thrive in “bioswale conditions.”
A bioswale is a landscape element designed to absorb stormwater and handle runoff – like a gently sloped drainage ditch that is fully planted. (A rain garden is similar, but typically smaller and less ditchlike.)
Buffalo now has several bioswales, a great example at the south end of the 4-acre Buffalo Niagara Medical Campus parking lot. The apparently simple, planted trench can divert 4 million gallons of stormwater from Buffalo’s sewer system every year.
What to plant? When rain gardens or bioswales first emerged, designers chose plants for moist sites. Trouble is – a bioswale site may be bordered by parking lots and highways and is often drought-stricken even longer than it is flooded. And watering is not possible. Some of the best plants that tolerate both wet and extremely dry sites (once established) include some familiar entries – gray and bloodtwig dogwoods, viburnums and dwarf or creeping willows.
Others may surprise you: Hippophae rhamnoides (Dwarf sea-buckthorn), Diervilla lonicera, Rhus aromatica ‘Gro-low,’ forsythia, ninebark, bayberry, Deutzia scabra, and even a St. John’s wort, Hypericum prolificum. For the entire stormwater shrub booklet: www.hort.cornell.edu/uhi/outreach.
Brenda Young, Daemen College professor, also addressed stormwater management. She charged landscapers with educating and revising customer expectations about landscapes: Limit the hard surfaces, choose permeable pavers, limit fertilizer and pesticide use, add green infrastructures. She defined LID – Low Impact Development – and encouraged the public and industry alike to adopt green roofs, rain gardens, rain barrels, permeable pavers and porous pavement. She also credited Buffalo’s Dave Majewski and other Buffalo leaders who have been developing Buffalo’s progressive Green Code – a big step forward.
Native plants, borders
The topic of invasive plants and alternative choices has been featured for many years – this year no exception. Native plant educator Ken Parker, now manager for the Seneca Nation’s Food is Our Medicine project, presented “Landscaping with Native Herbs, both Medicinal and Edible. Rochelle Smith, now with Finger Lakes Community College, built on the theme, showing vegetative borders using native plants.
Ironically, my role – usually an advocate for native plants and eco-friendly landscapes – was teaching about Proven Winners and other great shrubs for home landscapes, including the non-native hybrids that native plant purists eschew.
My message was not/is not in opposition to native plant advocacy though. Knowing that few people will or can go all-native, I simply ask us all to commit to just 20 percent native plants in our own yards. If you look at the plant lists that Ken Parker, Rochelle Smith and so many others offer, you will see that we have so many well-behaved, multitasking, lovely native plants to use, and most are now available in our garden centers. Going native, if only 20 percent, will not be that difficult. Try for 20!
Over the two days some serious disease topics were covered – the boxwood blight, rose rosette and impatiens downy mildew, presented by one of the top plant pathologists in the Northeast, Marge Daughtry. Ken Brown led landscapers through a protocol for diagnosing plant problems. Tom Mitchell – “plant teach” to hundreds of today’s landscapers, now at Niagara County Community College – taught weed identification and management, and an intensive review of soils.
Jean Bonhotel of Cornell’s Industrial Waste Management Institute updated the audience about industrial composting, including road kill composting. Just before lunch we were thoroughly enlightened about how some amazing little microorganisms break down entire animal carcasses! Only the extraordinary lunch at Salvatore’s Italian Gardens could have salvaged our appetites.
There was also fun to be had, if you like mentally exhausting, teeth-grinding competition. Carolyn Stanko, who is preparing NCCC students to be your landscapers of the future, was game-show host for Horticulture Jeopardy.
During it, NCCC students mixed with veteran landscapers and CNLPs of all levels, to buzz in the answers on soil, drainage, pests, plant physiology, pruning and organics. The tension was palpable, the will to win obvious, as these folks scrambled for the answers.
The most difficult part – making some of us quite aware of all we have forgotten – was the plant-identification contest, during which we had to name (Latin and common names) woody plants based on their winter twigs and buds. As teams, most did well. Individually? Well, that was partly the point.
Not every garden center owner, nursery or landscape firm invests in its employees’ education. Consider Plant WNY members, sporting a CNLP badge, a good bet for future projects. They keep on learning.
Sally Cunningham is a garden writer, lecturer and consultant.