Paul Roberts has been producing wine in Friendsville in Garrett County for 17 years. Last year, for the first time, his growing season began in March — six weeks earlier than the historical timeline.
It was “unprecedented,” he said.
For farmers and gardeners, climate change is making the art of coaxing a flower to blossom or fruit to grow precarious and unpredictable.
On Friday, horticulturists, biologists and activists talked about climate change in Montgomery County and how to adapt. They were part of a symposium called “Green Matters 2014: Gardening in a Changing Climate” at Brookside Gardens in Wheaton.
A midwinter thaw or an early frost can kill many plants and ruin crops. With increasingly extreme and unpredictable weather due to climate change, plants’ health is at the whim of the weather.
An early warm spell triggers fresh growth that is vulnerable to frost, Roberts said. When the growing season starts early, it means more nights for him to worry about the temperature dropping below freezing and damaging his crops.
The last two years, his winery, Deep Creek Cellars, lost about 20 percent of its crop. During the past 17 years, early growth has become more common, he said.
Jody Fetz, green management coordinator for the Maryland-National Capital Park and Planning Commission, said there’s not much gardeners can do except respond to the changes they see.
She offered tips for growing hardy plants and a list of species that can withstand different climates. If lily of the valley, for example, can withstand Minnesota’s winters — she’s a Minnesota native — it can survive the polar vortex that plunged into this region this winter, she figured.
Withholding water sometimes can strengthen plants by encouraging the root system to grow deeper in search of water, she said. Overwatered soil can create a too-inviting environment for pathogens that feed on roots.
With higher temperatures, pests can now survive farther north and at higher elevations than they have previously.
For example, speaker Michael Raupp, a professor of entomology at the University of Maryland, explained how the mountain pine beetle, which has ravaged western forests, is beginning to spread. He thinks it could start showing up in Maryland and feeding on jack pines. It is among a number of pests invading the area that used to live only in Southern states.
The mismatch of pollinators’ and plants’ schedules also threatens plants’ ability to reproduce and produce food. Plants and insects respond to changes in hours of sunlight and temperature. But if a pollinator emerges during an early temperature spike, the plants it pollinates may not be in blossom. Crops rely heavily on insects such as bees, whose populations have struggled in recent years.
Longtime Takoma Park gardener and Chesapeake Climate Action Network founder Mike Tidwell said seeing his own garden struggle spurred him to take on the root cause.
“Throughout the 1990s, I really started to notice the weather changing,” he said.
His organization works to fight climate change in the Washington metro region through political activism and encouraging people to reduce fossil fuel consumption. He said he’d like to see farmers and gardeners joining the charge in greater numbers.
Another speaker, Gary Nabhan, the chairman in sustainable food systems at the University of Arizona Southwest Center, discussed how traditional farming methods can help restore ecosystem health and biodiversity.
“I don’t think we have to feel like we’re starting over, starting from scratch,” he said. “There’s all this traditional knowledge.”
The U.S. Department of Environmental Protection estimates that the average global temperature will rise 2 to 11.5 degrees Fahrenheit by 2100. There will be more extreme weather events and unpredictability. Gardeners and farmers will have to adapt to and cope with continued change.
“One of our best bet-hedging strategies is to restore biodiversity,” Nabhan said. Biodiversity supports stable ecosystems that can bounce back from extreme weather. Growing different plants together, as they do in nature, increases biodiversity on farms, especially when those plants have symbiotic relationships.
As changes in climate begin to manifest in our gardens, croplands and even options at the grocery store, it might mean adjusting what we plant and how, and continuing the search for effective ways to stop adding and start removing carbon from the atmosphere.
Raupp suggested planting more in general, including rooftop gardens. Vegetation captures carbon, reduces temperature with shade and reduces runoff. When surfaces retain water, that water evaporates, cooling the Earth in much the same way that sweat cools people.