The Mid-Atlantic Region comprises the states of Delaware, Maryland, Pennsylvania, and Virginia as well as the District of Columbia. It includes the Chesapeake Bay Watershed and its three geological/topographic/climatic regions defined (and illustrated below) in Native Plants for Wildlife Habitat and Conservation Landscaping: Chesapeake Bay Watershed: “(1) the coastal plain, an area with fairly flat topography and more southern climate; (2) the Piedmont plateau, with its rolling hills; and (3) the mountain zone [Blue Ridge, Ridge and Valley, Allegheny or Appalachian Plateau], a more northern climate.” Although the Watershed extends from south central New York through the panhandle of West Virginia, those two states are not considered part of the Mid-Atlantic Region for purposes of the native plant fact sheets.
Northern Virginia (NoVA)
Northern Virginia includes the counties of Arlington, Fairfax, Loudoun, and Prince William, and the cities of Alexandria, Fairfax, Falls Church, Manassas, and Manassas Park. Native habitat data are reported by county. The Plant NoVA Natives logo appears only on the fact sheets of those native plants listed in its guide. To learn more about the Plant NoVA Natives selection criteria and campaign, click here.
The scientific name of the plant appears at the top of the page and follows the Flora of Virginia. If the scientific name has changed over time, then prior classification is noted in the introductory paragraph. For example, Persicaria virginiana was earlier classified as Polygonum virginianum or Tovara virginiana. Common name(s) are listed below the scientific name. When searching for a plant, it is best to use the species’ unique scientific name(s) since several different plants may share the same common name. For example, coneflower can refer to Echinacea, a perennial of nine different species or Rudbeckia, which includes annuals, biennials and perennials among some 25 accepted species.
In a few cases, a species’ cultivar may be mentioned (these names are enclosed in single quotation marks) in the introductory paragraph. In Northern Virginia, where garden size may be an issue, cultivars may be more compact, easier to contain, more floriferous or colorful and thus more suitable for limited garden space than the species.
Native Habitat Range and Status
The range in which plants naturally occur in the habitat is usually mentioned in the introductory paragraph. Their native status may be rare to common. In some instances, established populations may actually be escapes from cultivation and are so noted.
The USDA Plant Profile is the primary source for identifying native habitat range in the United States down to the county level. When species are not wide-spread throughout the Mid-Atlantic Region, a more detailed description of the native range usually is provided in a footnote in the bottom right-hand corner of the table and varies in terminology and specificity based on the source materials available.
The Digital Atlas of the Virginia Flora provides the most detailed comments about species habitat and status and is often quoted verbatim. FromThe Flora of Delaware Online Database, the Piedmont and Coastal Plain status is used. The Pennsylvania Flora Project of Morris Arboretum illustrates species distribution by county but rarely lists its state status so the fact sheets mostly describe where the species are located in the state. The USDA Plant Profile is used to determine a species presence or absence in the District of Columbia. The Plant Profile also is used for Maryland, but county data were rarely available. In cases where Maryland is not referred to, then species presence or absence in Maryland can sometimes be inferred based on the species frequency in the surrounding states.
Type of Plant
Plants are grouped into seven botanical (and color coded) categories: Ferns (strawberry), Grasses and Sedges (tangerine), Ground Covers (blueberry), Perennials (eggplant), Shrubs (clover), Trees (mocha), and Vines (maroon).
Height and Spread: The range given (usually in feet) is the typical height and spread of a mature plant grown in cultivation. However, plant growth can be affected positively or negatively by a variety of factors (e.g., soil, moisture, light).
Bloom Color: The most prominent color or range of colors are identified.
The first line in this section describes the form or general growth pattern of the plant (e.g., mat- or mound-forming, single- or multiple-trunked, conical or rounded shape) as well as the foliage type: deciduous (the default if not listed), semi-evergreen, or evergreen. The succeeding lines describe the physical appearance of the leaves, stems, flowers and fruit. To learn more about a particular botanical description, visit the “Botany: Plant Parts and Functions” chapter of the online Arizona Master Gardener Manual, which includes definitions and illustrations.
The bloom and fruiting periods and duration reflect what is typical in Northern Virginia although these may be accelerated, extended, delayed, or truncated by unusual seasonal or climatic conditions. The dioecism of a plant is noted if a separate male plant must be situated near female plants in order for them to produce fruit. Fruits and seeds are described when they are distinctive or interesting in form or attractive to wildlife. Likewise, fall foliage color and bark appearance and/or color are mentioned when they are notable and provide autumn or winter interest.
The major tolerances or sensitivities for each plant are listed, although the list may not be all inclusive. Tolerances are indicative of less than optimal growing conditions in which a healthy plant can survive but not necessarily flourish. For example, a plant tolerant of Black Walnut means that it may survive under the canopy of a Black Walnut tree without being adversely affected by the toxic chemicals that the tree produces. Sensitivities are external conditions to which an exposed, otherwise healthy plant is likely to have an adverse reaction.
A notation of “no serious pests or diseases” means that any pests or diseases normally associated with this plant are not likely to do it long-term or significant damage. A plant for which this is not noted may potentially be afflicted by numerous pests or diseases of varying consequence. If specific pests or diseases are likely to occur and could have a serious impact on the plant, an attempt was made to identify them.
However, the fact sheets are NOT intended to be comprehensive or authoritative in this regard. Further research should be done if there are questions regarding pest and disease susceptibility of a particular plant. You can obtain more information from publications on the Virginia Cooperative Extension and other state extension Web sites or you can contact your local extension office’s horticultural agent. A reputable nursery also should be able to answer your questions.
As more suburban and urban areas abut or encroach on wooded habitats, they increase the availability of the preferred habitat of white-tailed deer: the edges of mixed forests, with trees and shrubs to provide protective cover and open landscapes to provide graze and browse grounds. This and the absence of natural predators have caused deer to become more prevalent in residential environments, sometimes resulting in substantial damage to landscape plants. Landscape damage may be mitigated through cultural practices and by growing plants that nurseries have identified as “deer-resistant” or “deer-tolerant.” When possible, the fact sheets have attempted to qualify deer tolerance even further with the following labels:
Rarely Damaged: Plants that deer usually bypass in favor of other plants and that are the best candidates for deer-prone landscapes.
Seldom Severely Damaged: Plants that deer may browse but without significant damage to the well-being of the plant or its overall attractiveness; also good candidates for deer-prone landscapes.
Occasionally Severely Damage: Plants that deer eat once their favorite food sources are gone and can be severely damaged.
Frequently Severely Damaged: Plants that are sought out by deer as their preferred foods and often require protection.
Multiple sources were consulted (see Sources end References) to determine a plant’s deer tolerance, often with differing results. Almost all sources agree that deer are least likely to eat ornamental grasses, ferns, and strongly aromatic plants like herbs. They also agree that the plants most likely to be eaten are daylilies (Hemerocallis), Hostas, tulips, Violas, and arborvitae (Thuja). Other than that, a plant’s desirability to deer depends on its location, palatability, and stressors that may affect food supply (e.g., temperature extremes, rainfall patterns, flooding, snow cover) as well as on deer overpopulation, habit, and age.
The bottom line is that deer will eat almost anything if they are hungry enough and the amount and type of food available is scarce. If in question, consult your extension horticultural agent or your local nursery about a plant’s success at deer-resistance in your particular area or for methods to control deer damage.
The plant fact sheets are NOT intended to be comprehensive or authoritative with regard to plant toxicity or edibility. They are merely designed to provide general and basic information as space permits about plants that are potentially poisonous to or edible for people (not animals). To learn more about edible plants and for help in identifying them, consult appropriate field guides.
- Just because a plant is not identified as toxic does not mean that it is safe to eat.
- Sometimes only certain parts of a plant are edible and other parts of the same plant are toxic.
- Sometimes parts are only edible at a certain time in their life cycle or when they are prepared in a certain way.
- Plants identified as having ethnobotanic uses may have been used historically, but with modern research may have been found ineffective or even dangerous.
- Plants identified as having therapeutic uses may contain compounds extracted for use that are otherwise poisonous or may be made into drugs that may be dangerous in high doses.
- Plants identified as having herbal uses may or may not have been scientifically tested or proven effective. Although some may be taken without consequence, others may cause harm.
- Plants that are toxic or potentially harmful to humans may not be harmful to wildlife or domestic animals and vice versa.
There are various forms of plant toxicity. Children are more vulnerable to toxicity because of their size and weight and because they sometimes experiment, touching things that look pretty and eating things even if they do not taste good.
- Some plants can be harmful if ingested: they could result in serious illness or death or may just cause minor upset. Sometimes a plant may be harmful only if ingested in large quantities or with repeated doses over time.
- Some plants can be harmful if touched. The sap, thorns, etc. may cause irritation, contact dermatitis or more serious allergic reaction. Touching eyes, nose, or mouth without washing one’s hands after touching a plant is never a good idea.
The University of California, Davis recommends the following actions for treating exposure:
If the victim is choking and cannot breathe, call 9-1-1
– Mouth: Remove any parts of the plant from the patient’s mouth and clean out the mouth.
– Skin: Wash the area exposed to the plant with soap and cool water as soon as possible.
– Eyes: Flush eyes with lukewarm water for 10 to 15 minutes. Be very gentle, as vigorous or prolonged rinsing can hurt the eyes.
Meanwhile, call the Poison Control Center: (800) 222-1222
If you are advised to go to an emergency room, take the plant or a part of it with you (take more than a single leaf or berry). Take the label, too, if you have it. The correct name can result in the proper treatment if the plant is poisonous. If the plant is not dangerous, knowing the name can prevent needless treatment and worry.
Plants may provide food, protection, or nesting sites for a variety of wildlife, which are identified as space allows. Flowers may attract beneficial insects including pollinators like bees, flies, butterflies, and moths and pest predators like wasps; and hummingbirds. Seeds may attract birds, usually songbirds or small migratory birds, but other game birds, predatory birds, or waterfowl may be identified. Fruits and/or foliage may attract deer and small mammals like squirrels, chipmunks, opossums, rabbits, etc. Foliage also may serve as larval host for specific butterflies and moths. To learn more, see mgnv.org’s Resources section and click on Wildlife.
Soil preferences include texture: clay, silt, or sand; drainage (the rate and extent of water movement in the soil); fertility: rich (high in organic and nutrient content), average or poor (insufficient nutrients); and pH: acidic (pH 6.5 or less), neutral (pH 6.5 to 7.5), or alkaline/basic/sweet (pH 7.5 or greater).
Surface soils in Virginia tend to be some type of loam, which has moderate amounts of sand, silt, and clay. In sandy loam, sand predominates. It feels rough or gritty and does not hold together when moist. Silt loam feels smooth or floury when rubbed between thumb and fingers. Silty clay loam, where silt is still dominant, feels smooth when dry but becomes somewhat slick when moist. Lastly, clay dominates clay loam. It also feels smooth when dry but becomes sticky when wet.
In NoVA, soils have been mapped in many areas. To determine the type of soil on your property:
- In Arlington County, call 703-228-3629, TTY 711 or view a map online (pdf).
- In Fairfax County: Email the Northern Virginia Soil and Water Conservation District or call 703-324-1460, TTY 711 with your street address and staff can identify the soils at that location if the area has been mapped.
- In Loudoun County: Email the soil and water conservation district at: firstname.lastname@example.org or call 703-771-8395, TTY 711.
- In Prince William County: Email the soil and water conservation district at: email@example.com or call 703-594-3621, TTY 711.
Soil texture influences other characteristcs such as drainage and the amount of water, nutrients, and organic matter that soil can retain. Sandy soils drain quickly and their moisture retention, compactability, nutrient storage and supply capacity, and organic matter levels are all low. At the opposite end of the spectrum, clay soils tend to drain very slowly but have high moisture retention, high compactability, and high capacity to store and supply nutrients and organic matter.
The University of Missouri Extension Service defines well-drained soil as “that which allows water to percolate through it reasonably quickly and not pool…. A test that is often recommended is to dig a hole 12 by 12 inches square and about 12 to 18 inches deep. Fill it with water and let it drain. Then do it again, but this time clock how long it takes to drain. In well-drained soil the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in sandy soil, may signal potentially dry site conditions; a slower rate is a caution that you either need to provide drainage or look for a species tolerant of wet conditions.”
There are few things more important in gardening than good soil preparation. The top eight to twelve inches or so of soil are where plant roots grow so it is vital to amend soil when needed to improve soil texture, reduce compaction, improve drainage, and add nutrients. All soils benefit from routine applications of organic matter like compost (humus), leaf mold, or well-aged (not fresh) manure.
Organic material increases the ability of sandy soils to retain water and of clay soils to move water. To increase the capacity of sandy soils to hold water and store nutrients, you can also add sphagnum peat. To increase the permeability and drainage of clay soils, you can also add pea-size pine bark mulch or perlite. (Additionally, you can improve drainage by raising the beds.) Do not use peat moss, sand, or gypsum to amend clay soils. And, be aware that compost may contain weed seeds or plant pathogens and that manures might also contain weed seeds as well as undesirable salts. Mulching all soils will improve water absorption and moisture retention and cool soil temperature as well as reduce weed growth.
Although you can estimate soil texture by feel as described above and organic content by color – the darker the color (brown/black), usually the higher the organic content – only a soil test can determine your soil’s pH as well as the nutrient content. For more information about soil tests, visit the Virginia Cooperative Extension site at: www.ext.vt.edu and type in “soil test.”
- Sun: The site receives more than 6 hours of direct sunlight each day during the growing season.
- Partial Shade: The site receives 3 to 6 hours of direct sun. Morning sun and afternoon shade allow for a different range of plants than morning shade and afternoon sun (which is more intense).
- Dappled Light/Shade: Sun is filtered through leaves and branches.
- Shade: The site either receives less than 3 hours of direct sunlight or dappled light through the day.
- Dense Shade: Lack of sun presents one of the greatest challenges in plant selection. But, if the dense shade is seasonal – when developing leaves form a thick canopy – then plants that flower early spring and become dormant in summer may be an answer.
Watering requirements differ for established plants compared to newly planted ones. New plants or seedlings, even those that are drought tolerant, may require daily watering for the first week or so and then two or three times a week for the next month or two depending on the weather. Once plants have become established, though, water only when they need it according to the weather and the soil.
For most plants, the best practice is to water them deeply but less frequently to encourage deeper root development and increase drought tolerance. Good cultural practices such as watering in the morning and applying water directly to the soil (for example, with soaker hoses or drip method), lose less water to evaporation and reduce foliar diseases.
Growing the right plant in the right place also should result in less frequent watering. The exception is container plantings, which tend to dry out quickly. Container material, potting soil, and the amount of sun received also will all affect watering frequency.
- Dry: Water drains from a site quickly after rainfall. This is common in areas with sandy soils, on steep slopes, or where trees and shrubs with surface roots rob moisture from soil.
- Moist: Soil is damp and, on occasion, saturated. This is common in areas near springs, streams, or on floodplains that seldom dry out.
- Wet: Soil remains saturated for much of the growing season except during droughts.
Other Growing and Maintenance Tips
When appropriate, notes on special planting or care requirements are listed. These may include how to control unwanted spread and when to divide, transplant, prune, or cut back particular plants.
Plants have a variety of uses in the residential landscape. Besides their aesthetic appeal, you can take advantage of their growth habits and characteristics to solve landscape problems (e.g., control erosion, improve drainage), to control climate (i.e., shade a house in summer, provide a windbreak), to create architectural forms (i.e., use a hedge as a wall for privacy or to border property), and to improve habitat diversity (i.e., attract pollinators and other wildlife). The fact sheets provide a few ideas, but uses are only limited by the environmental conditions of the site and your imagination.
[The maps pictured below and the explanation of hardiness zones and microclimates are taken/quoted directly from the USDA Agricultural Research Service at http://planthardiness.ars.usda.gov/.]
The 2012 USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which plants are most likely to thrive at a location. The map is based on the average annual minimum winter temperature, divided into 10-degree F zones.
Hardiness zones are based on the average annual extreme minimum temperature during a 30-year period in the past, not the lowest temperature that has ever occurred in the past or might occur in the future. Gardeners should keep that in mind when selecting plants, especially if they choose to “push” their hardiness zone by growing plants not rated for their zone. In addition,…, there might still be microclimates that are too small to show up on the map.
Microclimates, which are fine-scale climate variations, can be small heat islands—such as those caused by blacktop and concrete—or cool spots caused by small hills and valleys. Individual gardens also may have very localized microclimates. Your entire yard could be somewhat warmer or cooler than the surrounding area because it is sheltered or exposed. ou also could have pockets within your garden that are warmer or cooler than the general zone for your area or for the rest of your yard, such as a sheltered area in front of a south-facing wall or a low spot where cold air pools first. No hardiness zone map can take the place of the detailed knowledge that gardeners pick up about their own gardens through hands-on experience.
Excellent Replacement for…
This section of the table lists the scientific and common names of invasive, problem, or non-native plants with similar characteristics that could be replaced with the native plant. To learn more, see mgnv.org’s Resources section and click on Problem Plants and Better Alternatives.
Many of the Mid-Atlantic native plant selections grow in local public gardens (e.g., Master Gardeners of Northern Virginia demonstration gardens, Central Library Garden (Arlington), Green Spring Gardens, Meadowlark Botanical Gardens, the U.S. Botanic Garden, U.S. National Arboretum, etc.). These gardens offer you an opportunity to personally observe the growth habits of these plants during different seasons and under varying conditions before making an investment for your own garden.
The five demonstration gardens designed and maintained by MGNV include the Glencarlyn Community Library Garden, the Organic Vegetable Garden at Potomac Overlook Regional Park, the Quarry/Shade Garden and Sunny Garden at Bon Air Park, all in Arlington County; and Simpson Gardens in Alexandria. Many of the gardens have signage, garden maps, and/or brochures with plant information. Additionally, Master Gardener volunteers are available during open “houses” in the spring or fall and during scheduled work parties to offer advice and answer questions.
Where possible, Master Gardeners have attempted to capture images of the native plant selections during various seasons so that you can see examples of flowers, foliage, fruit, and/or form on the fact sheets if you are unable to visit the gardens in person. They will continue to update fact sheets with new pictures as they photograph more specimens.
The photographer and location (when known) of each image are identified below the table. All images included in the Mid-Atlantic native plant selections fact sheets are the property of the photographer. For use of these images, please refer to the image use policy of MGNV (or to that of a cited organization).
Where to Buy Native Plants
If you purchase native wildflowers make sure that they have been propagated in reputable nurseries and not harvested from the wild. Native species that are threatened or endangered have mostly succumbed to habitat loss (especially from farming, suburban development), over-grazing, over-harvesting, poaching, or the introduction of invasive species. Look not only for a “native” label but for the species full scientific name to ensure that it is native to your region. Be sure to ask about a plant’s origin before you buy it. Native plants that have been raised locally are more likely to survive transplantation and to reproduce in your garden.
Some local nurseries specialize in native plants and other nurseries are increasing the availability of native plants among their offerings. Additionally, during the spring and fall, Northern Virginia, as well as other areas in the Mid-Atlantic Region, are host to numerous native plant sales. You can often find these advertised in local papers or listed on web sites – search for “native plant sales in Northern Virginia.”
In May, the Master Gardeners of Northern Virginia sell native plants at their booth at the Green Spring Gardens Plant Sale as well as at the Glencarlyn Library Plant and Herb Sale. Many of the plants have been divided or propagated from the plants in the MGNV demonstration gardens. Look for announcements of these sales on mgnv.org and on the Virginia Cooperative Extension – Master Gardeners of Arlington / Alexandria Facebook page. Maybe one or more of these native plants will find a home in your garden.