Edible Monterey Bay

ON THE FARM

Healthy Hedgerows

PHOTOGRAPHY BY COLINE LECONTE

Bringing nature back to the fields has many benefits


Wouldn’t it be amazing if the rumors were true? All we have to do is plant several billion trees worldwide and we can reverse global warming! This idea is so timely that it was just announced in the Philippines that students are required to personally plant 10 trees in order to graduate from high school. Trees sequester carbon from the atmosphere as they grow by breathing in the CO2 we exhale. Fortunately for us, trees exhale oxygen—a handy exchange. It’s how nature works. We’re part of it. But there’s more.

What’s not so easy to swallow is that the way we’ve traditionally grown our food accounts for nearly one-fifth of the world’s greenhouse gas emissions—a huge contributor to global warming. Much of this is caused by tillage—the backbone of industrial farming—not just burning fossil fuels in heavy-duty farm equipment, but actually releasing excess CO2 from the ground when crops are turned in to the soil at the end of the growing season. Those bare fields you’ve driven by? They may look weed free and tidy, but to reverse global warming, they need to stay green. What tools does agriculture have to accomplish this critical change in its practices?

Planting hedgerows around the perimeters of farm fields, including trees and woody shrubs, can be a huge help. Hedgerows act as living fences, barriers and boundary lines, stabilizing waterways and providing erosion protection. They also improve the water-holding capacity of soils and provide cooling shade during heatwaves. They are especially attractive to organic and regenerative farmers who strive to provide habitats for beneficial insects and pollinators who eat the pests bugging their crops.

Farmers may now apply for funds from the California Department of Food and Agriculture to pay for planting hedgerows through the Healthy Soils grant program. Next season’s allocation is $28 million, and Governor Gavin Newsom has made it clear that the Healthy Soils program is a passion of his.

One of the heroes of hedgerows, Sam Earnshaw, the founder of Hedgerows Unlimited, lives in our backyard. If you’ve been on the annual EcoFarm Bus Tour, you may have encountered Earnshaw, a longtime host along with Amigo Bob Cantisano.

A Santa Cruz County resident since the 1970s, Earnshaw became an essential planner of this popular EcoFarm tour because he got to know most of the area’s farmers as an organizer for the Community Alliance with Family Farmers. He hosted monthly breakfast meetings and farm visits where discussions of what has come to be known as “biological farming” prevailed, and in 1996 he began helping farmers plant hedgerows in San Juan Bautista and the Salinas Valley. With the advent of Healthy Soils grants in 2017, Earnshaw is busier than ever.

The CDFA is incentivizing farmers to try regenerative agriculture techniques and pays for supplies. They can choose among compost application, no-till or reduced-till farming or cover crops, but one of the most cost-effective techniques is adding hedgerows to the edges of farm fields. Earnshaw always uses California native plants because insects that combat pests have co-evolved alongside the natives.

When giving tours, Earnshaw often gets the question, “Aren’t those just bushes?” But before the popularity of hedgerows, it wasn’t so long ago that tractor-manicured fields with ditches for edges were a normal sight in our area. The “bushes,” Sam points out, are deliberately selected native shrubs, trees, perennial forbs and grasses providing many advantages beyond carbon sequestration.

Hedgerow evangelist Sam Earnshaw marks out a new planting at Live Earth Farm in Watsonville.

Hedgerow evangelist Sam Earnshaw marks out a new planting at Live Earth Farm in Watsonville.


Farm edges, unsuitable for planting, often became a tangle of weeds and weed seedbeds, so mechanical scraping and herbicide use prevailed for a time. Run-off (filled with chemicals), dust, wind and a proliferation of persistent weeds resulted. As part of the organic farming movement, solutions that emphasized biodiversity, nature and wildlife habitat began to emerge. Now that carbon sequestration is also desirable, the addition of perennial herbaceous and woody plants on farms helps balance the CO2 release caused by tillage.

When asked how the Pajaro and Salinas valleys used to look, an oldtimer closed his eyes and told Sam, “I see houses.” What he was talking about were all the small family farms with houses and barns dotting the landscape. Many of these farms maintained trees for shade and hedges for windbreaks and boundaries around their homes and fields. But as industrial farming took over, agricultural plots started looking like factory floors without walls. Earnshaw likes introducing the aesthetics of flowering, sometimes towering, shrubs and trees back into our rural areas.

“My goal in helping farms become more regenerative is to establish more habitat on the farms as part of their agricultural operations,” says Earnshaw. “Making biology part of agriculture and increasing awareness that growing food is a biological system leads to diversity.” Also serving the Natural Resource Conservation Service as a technical service provider, Earnshaw helps individual farmers research the most effective plants to use for their hedgerows, windbreaks, filter strips and grass waterways.

“Recently they asked if I could help with agroforestry,” he tells me. A good example is a high school in Morgan Hill where he helped plant a harvestable hedgerow including citrus, pineapple guava, lavender, rosemary and edible flowers.

One speed bump in advancing the popularity of hedgerows involved the E. coli scare in 2006. Food safety rules emphasizing sanitized food production made farmers wary of planting hedgerows that host wildlife.

But eventually a study by a group of scientists at UC Berkeley found that removing non-crop vegetation from farm fields contributes to foodborne pathogens. The reason is still under study, but Earnshaw believes buyers and inspectors of fresh produce need better training so they don’t alarm farmers unnecessarily. Farming involves soil, which must be properly washed from fresh produce. That’s where regulations can be more stringent, but we don’t do ourselves any favors by eliminating nature from farms.

In 2018, the CAFF and The Farmers Guild published the second edition of Earnshaw’s guide Hedgerows and Farmscaping for California Agriculture, which you can download from either website.

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