Plant Provenance:
The geographic location of a plant population, including the environmental conditions in which it evolved. Provenance is important in ecological restoration and horticulture because plants of specific areas are often adapted genetically to perform better in those regional conditions (see Ecotype).
Ecoregion:
A large area comprised of similar climate, soil, topography, and ecological communities. Ecoregions help categorize geographic regions with distinct biodiversity and are often used in conservation to ensure that plant species are within their natural habitats.
- The central Virginia area is largely bisected down the middle by the Piedmont and Atlantic Coastal Plain, with the Fall Zone (Atlantic Seaboard Fall Line) being a geologic boundary differentiating the two regions. Fun fact: the Fall Zone is responsible for Richmond's James River rapids!
- The Piedmont extents from the middle of Virginia westward to the Blue Ridge Mountains. It is noted for its rolling hills, upland habitats, and clay-heavy, often rocky soils. This region was historically dominated by oak-hickory forests.
- The Coastal Plain extends mid-state to the Atlantic coast. It is characterized by low topography, sandy or silty soils, and extensive wetland habitats and estuaries. This region includes the Tidewater area, which is influenced by the Chesapeake Bay and tidal rivers.
Ecotype:
A genetically distinct population of a species that has adapted to specific environmental conditions within its range. Ecotypes arise due to natural selection and can show differences in traits like drought tolerance, flowering times, cold hardiness, or growth patterns, even within the same species. Ecotypic variation is as a result of particular environmental trends. Individuals able to successfully pass on their genes establish a population best adapted to the local environment. Over a long period of time, a plant that grew in a mountainous region may have slight genetic and physiological differences to the same species that grew by a coastline. For example, salt tolerance in coastal populations or cold tolerance in high-elevation populations. If enough genetic differences accumulate, or a population becomes isolated, an ecotypic variation can become its own subspecies, variety, or entirely new species through a process called speciation. Note: by interbreeding a local ecotype with a non-local ecotype, those genetic advantages can become averaged out or lost in offspring.
Subspecies & Variety:
Refer to naturally occurring categories of variation within a species that exhibit distinctive traits, such as flower color, leaf shape, disease resistance, or habitat preference. These traits are genetically stable, inherited, and can be passed down to future generations. The difference between the two lies in the degree of differentiation, the factors driving their evolution, and their patterns of interbreeding. Subspecies typically exhibit more pronounced differences, often shaped by geographic or ecological isolation, which reduces interbreeding with other subspecies. Varieties, on the other hand, possess minor but detectable differences and often occur within the same plant population, where they can interbreed freely. In plant scientific naming conventions, a subspecies is indicated with "ssp." or "subsp.", while a variety is designated by "var."
Cultivar (short for "cultivated variety"):
A plant variety that has been selected and bred by humans for specific desirable traits, such as leaf or flower color, growth habit, size, disease resistance, fruit production, or sterility. Cultivars are typically patented and mass-produced, propagated asexually (through cuttings, grafting, or cloning) to maintain their unique characteristics for commercial value, ensuring consistency across plants. A cultivar of a native plant is sometimes known as a nativar.
Nativar (short for "native cultivar"):
Refers to a cultivated variety of a native plant that has been selected or bred for specific traits, such as flower color, growth habit, or disease resistance. While nativars are derived from native plants, they may differ genetically and ecologically from wild-type populations.
Genetic diversity:
Genetic diversity is lower compared to wild-type plants due to cloned mass production. Asexually propagated nativars, such as those grown from cuttings or tissue culture, are genetically identical, making them more vulnerable to disease or environmental stressors. Seed-grown nativars, when available, retain more genetic diversity but may still lack the full adaptability of wild populations.
Sterility:
A benefit for small gardens is that some nativars are sterile and incapable of reproducing by seed, or have a more compact growth habit than the wild-type species. This can help gardeners maintain a tidy landscape, but at the cost of these plants being unable to sustain themselves naturally. Sterile nativars also do not produce seeds that feed wildlife, such as insects and birds that rely on them as a food source.
Wildlife support:
Nativars may not support wildlife as effectively as their wild-type ("straight species") counterparts, particularly if selected traits alter ecological interactions. For example, sterile or closed flowers (such as double-flowered cultivars of Hydrangea arborescens) may reduce access to nectar and pollen for pollinators. Similarly, leaf color variants (Physocarpus opulifolius cultivars with red or purple foliage) may have altered chemical compositions, making them unpalatable to native insect herbivores that depend on the original species.
Hybrid parentage & mislabeling:
Some plants sold as nativars are actually hybrids, with parentage that includes non-native species (such as Lonicera hybrids). The hybrid status of these plants is not always clearly labeled, and commercial retailers may not distinguish between a true native cultivar and a hybrid of mixed origin. As a result, gardeners seeking ecologically beneficial plants may unknowingly introduce hybrids with reduced wildlife value.
Use for conservation:
In conservation efforts, certain disease-resistant nativars may help restore decimated native populations. For example, resistant cultivars of Fraxinus spp. (Ash trees) are being developed to combat Emerald Ash Borer devastation. However, in general, commercial nativars are not recommended for habitat restoration, as they often lack the genetic diversity needed for long-term ecological resilience.
Research & wildlife support:
Some research is being conducted to evaluate how nativars support wildlife compared to their wild-type counterparts. Organizations such as the Mt. Cuba Center are testing cultivar trials to assess pollinator attraction, nectar production, and ecological value, with surprising results in some cases.
Straight Species or "wild-type":
Refers to a native plant that is uncultivated.
Right Plant, Right Place:
A fundamental gardening principle that emphasizes selecting plants that are well-suited to the specific conditions of a site to ensure their success with minimal intervention. It's important for gardeners and landscapers to consider factors such as light exposure, soil types, soil moisture, climate, and local ecology. By matching plants to their ideal environment, gardeners can significantly reduce maintenance, conserve resources like water, reduce or eliminate the needs for fertilizer, improve longevity and health of a planting, and support local biodiversity.
This principle is especially important in native plant gardening and sustainable landscaping, where plant selection can enhance ecosystem health and resilience. We highly recommend learning the basic conditions of your landscape before choosing plants, and doing research on the species native to your area. There are many local professional landscaping services that will visit your land and provide tailored recommendations, plans, or offer installation of native plants. WBN does not currently provide this service to homeowners, but feel free to reach out to us for recommendations of service providers.
Light Exposure:
All plants need sunlight. Some are adapted to a full day of sunlight, others are adapted to the most indirect slivers of illumination. We break light exposure levels down into three simple categories:
- 〇 Full Sun: 6+ average hours of direct sunlight. Prairies, fields, meadows, beaches, boulevards, parking lots, roadsides, and hell-strips (the bit of land between a road and a sidewalk) are some examples.
- ◑ Part Sun: 3-6 average hours of direct sunlight. Forest edges and savannas, hillsides, east and west faces of buildings are examples. Part Sun and Part Shade are nebulous terms we combined for simplicity’s sake, to refer to an area that experiences a few hours of direct sunlight and shade. “Dappled light” is another common term, usually referring to areas with partially open tree canopies where some bright sunlight can squeak past for much of the day.
- ◉ Shade: 0-3 average hours of direct sunlight. Deciduous forests, sides of buildings and structures. “Deep Shade” refers to 1 or less hours of direct sunlight. Many woodland perennials are adapted to deep shade.
Soil Types:
Much of Virginia has dense native clay soil. But depending on your environment, or how the soil of your land was amended or replaced, you may have sandy, loamy, or rocky soil beneath your feet, or a combination. All plants have a preference for what soil type they grow in.
Clay or Heavy Soil:
Dense, slick and tacky when wet, hard when dry. Poor aeration, slow water absorption, poor draining, high mineral nutrient content, high compaction. Clay soils are valued for their nutrient content and ability to hold moisture, and many Virginia natives are adapted to clay soil. Species that like well draining conditions will usually not thrive in clay soils.
Sandy or Light Soil:
Loose, small particles of decomposed and worn minerals. Low nutrients, usually high aeration, low compaction, porous and easily draining, susceptible to water erosion. Often in alluvial areas such as floodplains, coastal areas, streams, and riverbeds. But also remnants of glacial activity and ancient dunes. Plants that grow in sandy soil usually have deep, wide-spreading fibrous roots to hold onto the soil. Many are adapted to flooding or drought.
Loamy or Just Loam:
A rich combination of clay, sand, and silt. Almost all plants will be able to grow well in loamy soil. It drains well and holds onto moisture, and is fertile with higher concentrations of organic matter. Loam is often the soil composition of forests, grasslands, riparian areas, and wetlands.\
Rocky:
Also known as shallow or gravelly soil. Thin, lean soils low in organic matter and quick draining. Comprised of irregular pieces of stone and rock particles. Occurs naturally in areas where topsoil is thin above bedrock, or where soil eroded away. Rocky soil is also present artificially in disturbed areas such as near gravel roadsides, railroad embankments, construction areas, urban areas, parking lots, and waste areas. Considered difficult for plants to grow in, and often occupied by those adapted to disturbance such as weedy and short-lived species, and xeric plants that grow at high mountainous elevations, ravines and cliffs. Such plants tend to be able to grow in conditions few other plants can survive.
Soil Moisture:
The average level of moisture to be found at ground level. All plants are adapted to specific moisture levels, with some able to grow in arid zones or wetlands, or a combination. We divide soil moisture levels into 4 different categories:
Dry Soil:
Also known as arid or xeric soil. Soils far from water sources, or in areas with low annual rainfall. Or due to its topography or composition the soil does not retain moisture long after precipitation, or due to high sun exposure will dry out quickly. The Virginia Piedmont has many dry, hilly, upland soils. Such soil may be high in clay, sand or rock content, and low in organic matter. Long-lived plants adapted to dry soils often have thick, deep roots (many prairie grasses) to efficiently collect water and stay anchored to steep topography, or store moisture in their roots and stems (cacti, stonecrops, succulents).
Average:
Also known as mesic soil. A soil with well-balanced or moderate level of moisture that is well draining and doesn’t completely dry out. Many forests are mesic, with the higher organic material at ground-level able to retain moisture for longer than inorganic soils, and the shade of tree canopies reduces water evaporation. Ecosystems with average soil may receive an moderate amount of rainfall. Generally not close proximity to bodies of water, or may be in upland sites nearby water sources that make soil retain average moisture.
Moist Soil:
Soils that are frequently wet but well draining, with some level of oxygen intact. This soil stays consistently moist and does not dry out. Seasonal flood sites, wet meadows, low elevation areas, stream or river edges, and floodplain forests are examples. Soil may be loamy, high in organic matter and lower in pH (acidity) due to the natural processes of decomposition. Plants that grow moist soil are adapted to higher seasonal precipitation and flooding, and are able to tolerate soils with lower oxygen levels. Plants preferring this soil type typically have strong, wide-reaching systems of roots to hold onto flooded soils.
Wet Soil:
Also known as hydric or boggy soil. This soil is water-logged and low-oxygen, characteristic of areas where water collects and does not drain. Pond edges, riparian areas, wetlands, and low coastal areas are examples. The Virginia coastal plain has many wetland environments where species have adapted to only live in the stagnant, boggy soils. Some plants (such as Cardinal flower, Lobelia cardinalis) are "hydrophytes" adapted to grow within or even completely submerged in water.