Farm for wildlife with hedgerows
By Jarrod Fowler, Sarah Foltz Jordan, & Eric Lee-Mäder, Xerces Society
The U.S. is currently undergoing the largest conversion of wildlife habitat to cropland since just before the Dust Bowl. Over 11 million acres of prairie have been converted to cropland since 2008. A report released in 2014 by the London Zoological Society analyzed populations of more than 3,000 species (birds, mammals, fish, reptiles, etc.) and concluded that the Earth has lost half of its wildlife in the past 40 years.
How do we begin to bring wildlife habitat back to our farms? Conserving and creating hedgerows is a great place to start.
Hedgerows are linear plantings of dense vegetation, commonly native woody shrubs and trees. They provide fantastic opportunities to conserve wildlife, sustain agriculture, and yield profits in previously unproductive areas of your farm. Your infertile farm edges can become fertile refuges for plants and animals that provide valuable ecosystem services. If you plant hedgerows, wildlife will follow.
History tells of thorny hedgerows that thwarted Julius Caesar during 57 BC on the borders of Belgium and France and during 55 BC in Britain. Living fences of brambles and hawthorns enclosed and protected fields and stock from animals and thieves. Fast-forward nearly 1,600 years, British hedgerow planting evolved to become a best farming practice, championed by Thomas Tusser’s 1557 book, A Hundred Good Pointes of Husbandrie. Unfortunately, the heritage of British hedgerows grew derelict and suffered losses due to the Industrial Revolution, two World Wars, and accompanying agricultural intensification. The Countryside Commission of England reported that over 96,000 miles of British hedgerows were removed between 1947 and 1985—more than 12 times the diameter of Earth.
For nearly a decade, the Xerces Society has worked with farmers to plant hedgerows across the United States. Often these plantings follow the property boundaries of small farms and integrate into enormous interconnected networks that extend for miles.
Benefits of Hedgerows
Hedgerows provide farms with environmental, social, and economic values. For example, hedgerows support wildlife with food, such as nectar, pollen, foliage, fruits, as well as undisturbed soils and stems for shelter. The same hedgerows can intercept, reduce, and screen airborne pollution, such as chemicals, dusts, and noises, while sequestering carbon in biomass and soils. These living fences simultaneously beautify farms and offer cultural and ornamental resources, including wicker for basket weaving and poles for plant supports. What’s more, hedgerows provide humans with foods, medicines, and other products, such as fruits, nuts, herbs, and firewood. Harvests of hedgerow fruits for jams, jellies, syrups, tinctures, and teas can be abundant, nutritious, and profitable.
Research has shown that hedgerows export pollination and natural pest control services to adjacent crops. For instance, recent studies in California have investigated whether restored native hedgerows increased native pollinator abundance and diversity in comparison to unmanaged field borders. The results: farms with restored hedgerows host more native pollinators than control sites (Figure 1). In addition, restored hedgerows do not act as sinks for native pollinators, but rather as sources of native pollinators for adjacent fields (Figure 2).
Hedgerows also increase natural pest control on farms. To examine this, the Xerces Society collaborated with research partners to raise pests in labs, have the pests lay eggs on sticky cards, stake the sticky cards out in farm fields with and without hedgerows, and count how many pest eggs were attacked by beneficial insects. The result: farms with hedgerows consistently show higher numbers of pest predation than farms without hedgerows (Figure 3).
Overall, research shows that creation and conservation of hedgerows on farms enhances native beneficial insect communities, and exports ecosystem services to adjacent crops. Such contemporary concepts actually bolster age-old practices that work with nature to increase productivity and resilience on farms.
Site & Plant Selection
First, assess the farm and spot appropriate locations for hedgerows. In general, longer hedgerows with mature widths of 10-15 feet are best, but shorter and narrower hedgerows work well for small sites. Flat or gently sloping sites in full sunlight that are easily accessible, have minimal weed pressure, and are protected from pesticide drift are key for successful hedgerows.
Once you have settled on a suitable site, plant selection can begin. To start with, familiarize yourself with natural plant and animal communities in your area, and use this knowledge, along with site-specific climatic and soil conditions, to guide your plant selection. Select a set of native plant species that blooms throughout the growing season and provides nutritious nectar, pollen, foliage, and fruit.
One rule of thumb is to select around nine species, including a minimum of three that bloom during each season: spring, summer, and fall. If you know when your crops and neighborhood flowers bloom, then you can design the percentage of each hedgerow species to complement the bloom availability. For example, if you have an apple orchard that provides late spring bloom, you may wish to focus on early spring, summer, and fall blooming species. Avoid selecting non-native plants and plant species that might serve as alternate hosts for crop pests or diseases. For example, hawthorn is an alternate host for fire blight and might want to be avoided in orchard plantings.
Some of our favorite native woody plants for hedgerows in the Midwest include: basswood, blackberry, blueberry, buttonbush, chokeberry, chokecherry, currant, dogwood, false indigo bush, hawthorn, hazelnut, leadplant, New Jersey tea, plum, raspberry, red elderberry, red maple, rose, serviceberry, silver buffaloberry, snowberry, sumac, viburnum, white meadowsweet, willow, and winterberry holly. Most of these species are suitable for a range of site characteristics, but please consult with your local native plant specialists and online resources such as The Biota of North America Program’s North American Vascular Flora or United States Department of Agriculture, Natural Resources Conservation Service (USDA-NRCS) PLANTS Database.
The various plants in your hedgerow do not need to be represented equally. For example, traditional British conservation hedgerows are standardly composed of over 50 percent hawthorn for both stock-proof density and wildlife values. A comparable Midwestern hedgerow mix may include:
• 60 percent hawthorn
• 10 percent blackberry
• 10 percent willow
• 5 percent silver buffaloberry
• 5 percent New Jersey tea
• 5 percent false indigo bush
• 5 percent white meadowsweet
Preparation & Planting
After plants have been selected, the site-preparation process can proceed. Site-preparation is one of the most important parts of successfully establishing a hedgerow. The more time spent reducing weed populations before planting will result in greater success for hedgerow plants. Sometimes, site-preparation can take multiple seasons to adequately reduce competition from invasive, noxious, or undesirable weeds before planting.
Site-preparation methods for organic growers may include sheet mulching, smother cropping, and soil solarization. Site preparation could also include the creation of a 3-foot tall and wide earthen berm as a hedgerow base. You can create a berm by excavating and mounding soil from parallel ditches alongside the hedgerow. Hedgerows planted into berms can provide greater drainage, screening, and windbreak benefits. Fieldstones can be added to hedgerow berms to provide more height and structure.
Once the site is sufficiently prepared, nursery stock may be manually planted with shovels or mechanically installed in single-furrow-plowed trenches, plowed ridges, or spaded notches. Measure the planting areas prior to purchasing transplants and stage the transplants in the planting area prior to installation.
Plant sizes at maturity should be considered when staging. Most woody shrubs can be spaced on 4-foot to 10-foot centers, depending on sizes at maturity and your goals for the hedgerow. For stock-proof hedgerows, transplants are traditionally spaced at 8 inches. (That is a lot of hawthorns!)
Installation can happen any time the ground can be worked, but should be timed to avoid extended periods of dry, hot, or windy weather. Spring and fall are typically great times to transplant shrubs and trees.
All transplants should be deeply watered immediately after planting. Holes for plants can be dug and pre-watered before planting. Compost should be incorporated during planting in areas where the soil is compacted, degraded, or depleted. Make sure that transplants receive at least 1 inch of water per week either from rain or irrigation for the first two years after installation.
Apply a layer of bark mulch, wood chips, or weed-free straw to your hedgerow to reduce weed competition and retain moisture. During and after hedgerow establishment, manage weeds and protect plants from deer or rodents. Selectively prune hedgerow shrubs and trees outside of wildlife nesting seasons and never more than 30 percent during any year.
Financial & Technical Assistance
The USDA’s Natural Resource Conservation Service offers two programs, the Environmental Quality Incentives Program (EQIP) and the Conservation Stewardship Program (CSP), that could help fund your hedgerow projects. Contact your local NRCS field office (see nrcs.usda.gov) to ask about opportunities. The NRCS also can provide technical assistance for hedgerow planning and installation. Ask about practice code 422.
Hedgerows are a great asset to a farm. They’re also a smart way to increase the value and performance of the buffer areas around fields. For more information about hedgerow plants that attract pollinators, see www.xerces.org/fact-sheets.
Jarrod Fowler works for The Xerces Society as a pollinator conservation and conservation biocontrol specialist for the Northeast Region. Sarah Foltz Jordan is a pollinator conservation specialist for the Great Lakes Region. Eric Lee-Mäder co-directs the pollinator program.
From the May | June 2016 Issue