Citrus Island?

Greetings from Florida, where I’ve been enjoying warm weather and citrus fruit, and thinking of home.

Have you ever wondered why lemons are not grown on Shelter Island?

The U.S. Department of Agriculture has a map for you. The Plant Hardiness Zone Map helps people who grow things figure out which plants are most likely to make it through the winter, and the map, which was just revised for the first time in 10 years, still shows that Shelter Island (Zone 7a) will not have a citrus grove any time soon.

Plant hardiness zones are based on the average annual extreme minimum winter temperature, and the new map is about one quarter-zone warmer than in 2012 for much of the United States. The Department of Agriculture even added two new zones, 12 and 13.  These are areas with minimum temperatures above 50 degrees and 60 degrees Fahrenheit; warm enough to store apples.

Although the Department of Agriculture warns against drawing any conclusions about global warming based on these maps, they are literally a redrawing of the American agriculture scene, showing that the lowest likely winter temperatures are now 2.5 degrees Fahrenheit warmer on average than in 2012.

When I spoke with Arielle Gardner, the farm manager at Sylvester Manor about the realities of farming in a changing climate, she was putting on her boots ahead of a day in the mud. It was the first day in March, and many hours of soaking rain was about to turn the fields at Sylvester Manor into the kind of hog wallow that is not conducive to planting.

Unpredicted weather is every farmer’s nightmare, and climate change has made predictions much harder. “Last year every single Saturday it rained,” Arielle said. “The year before was drought. This year it’s really wet, and you can’t put a tractor in a muddy field.”

Long-time gardeners have noticed the change. In 1960, Suffolk County was Zone 6b and Shelter Island farmland (which constituted most of the Island) was in potatoes and lima beans. The 200-year old boxwoods at Sylvester Manor and the copper beech planted in the 19th century were going strong.

By 1990, Shelter Island was in Zone 7a. Tim Purtell, who has gardened here for decades, said he’s noticed changes. “Lilacs and other spring blooming plants bloom several weeks earlier than they did in the 70s, and our winters aren’t as cold,” Tim said. “Crepe myrtles are now abundant on Long Island. That would not have been possible 50 years ago. This is partly due to hybridization but also less cold winters.”

I asked veteran gardener  Wendy Mead if she’s seen the climate change on Shelter Island. “I just have plants that have always survived, so they don’t know the difference,” Wendy said. “I still have my rosemary in a pot on my front porch and it’s going strong. Usually, things in pots freeze when it gets to be in the 20s. That’s about the only thing I can say that I haven’t been able to do in the past.”

Arielle is leaning into no-till farming at Sylvester Manor, a practice that maintains the structure of the soil. “It’s in the last 10 years that this has become the forefront of agriculture,” she said. “You don’t have to water as much, you don’t have to weed. Organic matter does not allow for weeds to crop up.” 

Arielle explained that no-till practices are labor-intensive, but effective. “Soil is like our brain. If you put your brain in a blender every year, you have to re-learn and scramble up all these networks. No-till keeps the networks intact.”

She likes to grow plants that want to grow here, and stay away from plants that, while popular, may not be suited for our current climate. There will be some new crops grown on Shelter Island, but kumquats and limes will not be among them. Arielle grew okra last year (the key ingredient in my fried garam-masala okra) because okra thrives here. She plans to grow a pink variety this year.

Another long-time Island gardener, Kirsten Lewis, has gone the way of regenerative, sustainable agriculture, although she doesn’t call it that. “I have beautiful and strong invasive weeds which I’ve collected from around the Island in my garden,” Kirsten said. “My ‘normal’ plants are on the porch in the summer — away from the deer.”