TOP STORY — July 11, 2017

MNLGA field day attracts hundreds


Staff Writer

More than 330 members of the Maryland Nursery, Landscape and Greenhouse Association gathered at Ruppert Nurseries on June 29 for a field day.
Registrations reached a record level before having to be closed, said Vanessa Finney, MNLGA executive director.
The cut-off was necessary, not because of lack of space on the 600-acre nursery, but because of the difficulty of transporting that many people around the farm.
“It was a good problem to have,” Finney said.
Transportation issues were solved by pressing tractor-drawn hay wagons, landscape trucks and wagons borrowed from a local orchard into duty as people-movers.
This assortment of conveyances took visitors to educational stations on the farm where they learned more about cover crops of daikon radish and crimson clover, conservation strips as habitats for beneficial insects, use of compost and biosolids, drone use, invasive species, diseases and insect problems.
After a barbecue lunch, tours were offered of the entire nursery, including a behind-the-scenes look at liner planting made easier with a machine, demonstration of large tree digging and preparation for shipment and pruning techniques.
After a couple of hours in the field, at temperatures nearing 90 degrees, a “happy hour” with cold refreshments and some great music was much appreciated.
The field day kicked off under a big tent with some updates on the MNLGA itself. MANTS — the Mid-Atlantic Nursery Trade Show held in January — had been “phenomenal,” with the highest attendance since 2008 indicating a revival of the industry. Chesapeake Green, in its 13th year, “blew attendance figures out of the water” at a new venue, with an awesome lineup of speakers.
Keynote speaker Michael J. Raupp, entomologist at the University of Maryland, discussed some of the biggest threats to sustainability of nurseries and landscapes in general from an entomological standpoint.
Perhaps the worst of those problems is the importation of exotic, invasive species to the United States.
The rate of invasion hasn’t changed since 1860, Raupp said. It was the Industrial Revolution, when steamships made it possible to get to or from China in four days, that intensified the problem.
Waves of different exotic pests have changed throughout time. The USDA had a hand in bringing in exotic pests, through a program designed to find ornamental species to bring to the country.
“With a global economy, we have global biota”, Raupp said. “It’s not going to stop, so be prepared.”
Borers are riding the current wave of importation, and human diseases are coming in with insects such as mosquitos carrying yellow fever and zika virus.
These mosquitos are now present in Maryland, he added. “They overwinter under the Capitol Building in Washington, D.C.”
Climate change ranked second on Raupp’s list. As temperatures warm, insects and mites will become active earlier in the year and remain active later in the year. In the last 40 years, Raupp said, he has seen insect activity start up to two weeks earlier.
Just as bad, some insects and mites will be able to complete more generations per year. “Spider mites go from egg to egg-laying in seven days, not 30,” Raupp said.
When drought accompanies warmer temperatures, plants are stressed. That’s good for borers, which can be lethal. Normally, a tree responds to borers by pushing them out with sap. In a drought, they cannot.
With milder temperatures, southern pests move north, and they are able to spread to higher altitudes.
Another threat is the lack of plant biodiversity in urban forests. The lack of diversity can lead to catastrophic loss. Diversity is “Mother Nature’s defense in a changing world,” Raupp said.
Native plants provide resources for native organisms. Using exotic plants negatively affects the food web and allows outbreak of exotic pests for which there is no natural defense.
Hardscapes — impervious surfaces — are the No. 1 enemy of plants in the city. They create heat islands and reduce water infiltration.
Overuse of fertilizers and pesticides also pose a problem.
How can we enhance sustainability? Raupp had some suggestions:
• Provide better protection to keep exotic pests out. Legislative change is needed, as are the tools, education and training to detect these pests earlier;
• Mitigate climate change through reduced use of fossil fuels and plant more trees, shrubs and ground covers to take up carbon dioxide;
• Increase biodiversity at all levels.
• Use native plants when possible to provide resources for pollinators and beneficial insects;
• Replace impervious surfaces with permeable ones, and provide more green spaces; and
• Apply soil amendments, including nutrients and pesticides, on a prescription basis, using alternatives to pesticides whenever feasible and choosing those that are least disruptive to natural enemies and pollinators.
“Remember, this is a community of living organisms we are dealing with,” Raupp concluded.