Minutes September 26 — Native Grassland Restoration

Gardeners Exchange Group Meeting 26 September 2015
Location: Otto Farm at the Antietam National Battlefield Park
Topic: Native Grassland Restoration by Park Ranger/Natural Resources Technician Chris Tawney
Submitted by Julie Neely, GEG Secretary

Chris Tawney discussed the Park’s extensive restoration and preservation effort which has resulted in not only great beauty and appreciation and respect for the significance of the battlefields but increased habitat diversification for native birds and pollinators.

Antietam National Battlefield Park

Antietam National Battlefield Park consists of roughly 3300 acres. Prior to WWI the land was owned and used by the War Dept as a training ground for Napoleonic battlefield tactics. Battle field tactics began to change, Napoleonic tactics were deemed obsolete and the land was finally transferred to the National Park Service in 1933. Currently some of the parkland is leased to local farmers who are permitted to plant and harvest as they choose; this reduces maintenance costs to the National Park Service. The land bounding the battlefields and the waterways is maintained by the Park Service as a “scenic easement.”

Back to 1862

One of Antietam National Battlefield’s missions is to restore the park’s cultural landscape to the very scene as it would have appeared in 1862 during the actual fighting in this location at Burnside Bridge near Otto farm. Much of the area we visited would have been farmland: plowed fields and corn, as virtually no forested land existed in this area at the time of the battle. Approximately 70 total acres of fallow land was acquired in 2003; currently about 35 acres are undergoing restoration but all 70 acres are planned for inclusion in the grassland restoration project. Chris has initiated the installation of native grasslands in an effort to simulate the topographical perspective of the soldiers fighting the battles on this land to promote cultural awareness of the tremendous hardship and significance of their efforts. Over 23,000 men were killed in a single day at Antietam on 17 September, 1862. By way of comparison, that is approximately half the number of men who died in the entire Vietnam war.

The first step in the restoration process is the removal of the invasive trees such as autumn olive (Russian olive), Tree of Heaven (Ailanthus altissima), box elder, etc. After the trees are removed, a controlled burn is conducted on the land. Chris recommended burning in early spring. Permission from local fire departments must be obtained before controlled burns can be conducted. The first step is to define the area to be burned. The perimeter is mowed low and made wet in order to control the spread of the fire beyond the prescribed area. A line of fire is lit using a mix of gas and diesel and a special torch, and the burn is conducted in segments/strips to keep the fire under control. Once the fields and shrubby invasives are burnt off, the native warm season grasses can be planted. Chris recommended planting in mid- to late June when the temperature is around 65 degrees. Grasses planted include: big and little bluestem, switch grass, India grass, and Virginia wild rye; native flowers and plants that have been introduced include nectar sources such as black eyed susan, partridge peas, cone flower, coreopsis, milkweed, etc. Grasses are planted with a special seed drill but some seed is surface sown. Both methods seem to work as long as surface thatch has been burnt off prior to seeding. Surface sown seed can be mixed with organic kitty litter (no fragrance or disinfectants) for better soil adhesion and germination results. Warm season grass seeds are kind of fluffy/chaffy and somewhat difficult to get into the dirt. Seed sown in the fall seems to benefit from winter freeze and thaws. The first year’s growth of warm season grasses is somewhat underwhelming—do not be discouraged, it is growing roots beneath the surface and will prosper in the second year, provided you keep down invasives and cold season grass growth. Chris prescribes selective herbicide use (Plateau) on Johnson grass, Canada thistle, and other noxious weeds to reduce the competition on the native grasses; this herbicide treatment is conducted in late fall when the warm season grasses have gone dormant and the cold weather weeds are very obvious. Subsequent controlled burns are beneficial to native grasses and are planned every two to three years.

Benefits to Wildlife

Native grassland provides a habitat for many grassland nesting birds and small mammals who can only live in grassy meadows among the grass clumps, burrowing through the grass blades and bunches. Chris is especially interested in increasing the bobwhite population through habitat restoration for these birds, whose population is now only 1% of the number counted in 1966. Bird watchers will note that the restoration project is working as the list of birds seen along the trail increases. Blue-gray gnatcatchers, field sparrows, towhees, yellow-breasted chats, common yellowthroats, willow flycatchers, prairie warblers, blue grosbeak, goldfinches and cardinals can be seen throughout the year along the Final Attack Trail.

The wildflowers being introduced, especially milkweed, are helping to support the dwindling monarch butterfly population, which is said to be 90% less than the number that existed in the 1990’s. This drastic fall in monarch numbers is thought to be due to habitat destruction and herbicide used in industrial farming techniques which prevent the growth of plant life including milkweed in farmed fields. Monarch butterflies rely on the milkweed as part of their life cycle and protection from predators. In the larval stage, monarch caterpillars feed exclusively on milkweed. The milkweed they ingest is actually a poisonous toxin which makes them unsavory and avoided by predators. Planting and encouraging milkweed growth is a great way to help increase monarch numbers in your area. For more information about what you can do to help Monarch butterflies see the Monarch Butterfly Alliance.

Establish Your Native Grassland

For information and help establishing your own native grassland, Jim Rumsey of Sustainable Solutions, a resource management company, was recommended. They can help you plan your landscape, conduct a controlled burn and plant native plants and grasses for a reasonable fee. Also recommended was the seed catalog from Prairie Moon Nursery, the Native Gardener’s Companion, Seeds and Plants of Authentic North American Wildflowers for Restoration and Gardening. For more information on warm season grass and sources of grass seed see Earnst Seed, Native Warm Season Grasses. For more information on what you can do with your own property to promote grassland birds refer to the Potomac Valley Audubon Society Grassland Birds Initiative.