Virginia is divided into seven main ecological regions: the Middle Atlantic Coastal Plain, the Southeastern Plains, the Piedmont, the Northern Piedmont, the Blue Ridge Mountains, the Ridge and Valley and the Appalachian Plateau. Unique in topography, soil depth and pH, elevation, light and hydrology, each region provides a rich variety of ecological habitats, supporting many native plant species.

Northern Virginia encompasses a portion of the Northern Piedmont, as well as a small portion of the Northern Coastal Plain. It includes the counties of Loudoun, Prince William, and Fairfax and the cities of Alexandria, Arlington, Falls Church and Manassas.

The Piedmont is Virginia’s largest region. It is a region of low rounded hills, irregular plains, and open valleys. It is bordered by the Fall line to the east and by the Blue Ridge Mountains to the west. The fall line is a major break in geologic structure between the Piedmont and the Coastal Plain which results in differences in ecosystem patterns and a variety of landscape relief and roughness.

Northern Virginia is home to many species of trees, shrubs and flowering plants. It can also support many non-native species which are beginning to make their way across the landscape. Regrettably, some of these exotic immigrants are invasive and are threatening the native flora and ecology of the state.

According to the U.S Forest Service, Invasive species have contributed to the decline of 42% of U.S. endangered and threatened species, and for 18% of U.S. endangered or threatened species. Invasive species compete directly with native species for moisture, sunlight, nutrients, and space. They displace and alter native plant communities, degrade wildlife habitat and water quality, and potentially lead to increased soil erosion.

The federal government has estimated that nearly 25 percent of the 20,000 plant species native to North America are at risk of extinction, many of these through habitat loss. You can help reverse this trend by planting great native plants in your garden.

A plant is considered native if it has occurred naturally in a particular region or ecosystem without human introduction. There are many benefits in growing native plants.

• First, these plants are better adapted to soils, moisture and weather than exotic plants that evolved in other parts of the world. They need less fertilizers, pesticides or use less water.
• Second, they are unlikely to escape and become invasive, destroying natural habitat.
• Third, they support wildlife, providing shelter and food for native birds and insects, while exotic plants do not.

Here is a list of sun-loving native annuals and perennials that are well-suited for plantings in gardens of Northern Virginia.

• Never collect native plants from the wild as it will deplete natural ecosystems. 
• When possible, plant species grown straight from local seed sources. These native originals are the best choice, as they co-evolved with specific wildlife, which supports migration, breeding and other seasonal interdependency.