Our Restoration Work

We work to restore native plant communities on the Clifton Institute’s 900 acres, and we advise private land owners and government agencies on how to restore the lands they manage. By eliminating non-native plants and planting native species, we rebuild degraded habitats which allows declining plants and animals to recover and thrive. We use our research on native plant communities and declining birds to guide our restoration work and the advice we give. We continue to refine our methods and advice based on the results we observe at the Clifton Institute and at participating properties around the region.

Our grasslands on the left and our shrublands on the right.

Invasive Plants and Declining Species

Non-native invasive plants are degrading ecosystems across eastern North America. Non-native plants exclude native plants and fungi, and non-natives provide poor habitat for animals. For example, research by Doug Tallamy at the University of Delaware has shown that Autumn Olive leaves are eaten by just 5 species of caterpillars, while more than 400 species can eat oak leaves. This obviously affects butterflies and moths, but it’s also of critical importance to birds, who feed thousands of caterpillars to each of their chicks.

We focus our land management and restoration work on early successional habitats (areas that have been disturbed by mowing, fire, or grazing and are re-growing into forests) and declining species found in these habitats.  Grasslands, shrublands, and forest edges are especially vulnerable to invasion. Furthermore, these habitats support a disproportionate number of species that are declining across their geographic range. Grasslands in our area host American Kestrels, Grasshopper Sparrows, Eastern Meadowlarks, and Bobolinks, all of which are in decline. Prairie Warblers, Field Sparrows, and Yellow-breasted Chats are declining birds that inhabit shrublands. We manage our land and advise others to manage their land to help all of these species.

Restoration Actions

We use several different methods to remove invasive plants and encourage native species on the Clifton Institute property, and we compare their effectiveness with scientific research:

• Prescribed fire
• Bushhogging and mowing
• Cattle grazing
• Discing (plowing)
• Herbicides

There is no land management silver bullet. Each method has pros and cons:

• We use prescribed fire because native grasslands in our region were maintained historically partly by fire. So, many native plants benefit from burns, but some non-natives do as well.
• Cattle have some negative effects on the landscape, even when they are managed well. But our native grasslands are adapted to bison grazing, and some declining species such as American Kestrels and Grasshopper Sparrows select cattle pastures above all other habitats.
• We minimize the use of herbicides whenever possible, we are testing the effectiveness of different organic alternatives, and we present all management options to landowners. But organic alternatives such as discing and solarizing with plastic also have significant downsides (carbon release and killing soil microbes), so the choice of method is not clear cut. Some invasive plants that we are fighting (e.g. Wavyleaf Basketgrass) cannot be controlled at scale with organic methods. Finally, the costs of organic methods make them inaccessible to some landowners.

Prescribed burn in our shrublands in early 2019

Native Plant Propagation

We propagate native plants to distribute to landowners and to use in our restoration projects and gardens. Each year we collect seeds of 70+ species of native plants. We store seeds for native meadow plantings and we grow seedlings; each year we sell around 1,500 plants. We focus our propagation efforts on herbaceous perennials and grasses, with an emphasis on species that are not available from commercial seed sellers. We are also working with partner organizations and individuals to plant rows of priority species for seed production.

Volunteers help to clean seeds for our native plant propagation program.

Our Gardens

Thanks to the generous support of the Warrenton Garden Club, we were able to install a native plant garden at the farm house in the fall of 2018.  The garden serves as habitat for native animals and it allows us to teach visitors about the value of native plants right off of our front porch. Most programs at Clifton start at the farm house so the garden engages visitors as soon as they arrive. We also have a garden that is made up of 100% local-ecotype plants are native to Fauquier County grasslands.

Summer campers learn about the plants in our native plant garden

Restoration Successes

Our restoration projects are working!

• We observed that removing Autumn Olive from one of our fields in 2018 allowed Little Bluestem, Slender Lespedeza, and Gray Goldenrod to sprout from the seed bank in the soil and recolonize the field.
• We observed substantial increases in Early Goldenrod, Little Bluestem, and Indiangrass after presscribed burns in 2020 and 2021, to the detriment of non-native Tall Fescue.
• A single spray of herbicide in the winter of 2019 in our restoration experiment (see Research) killed the dominate non-native grasses and allowed the native New York Ironweed, White Vervain, and Crownbeard to re-colonize the field.

Get Involved

We are always looking for volunteers to help with our restoration work. We rely on generous people to help us with control of non-native plants, propagating plants, and maintaining our gardens. If you’re interested in helping out, you can find upcoming volunteer days on our calendar. Thank you!

Executive Director Bert Harris and a group of volunteers work on removing Autumn Olive.