One of the joys of living among Western North Carolina’s mountains is discovering wildflowers—alone or in profusion: beside a hiking trail, along the roadside, or in an open meadow. Some 300 different wildflower species grow along the Blue Ridge Parkway, and 1,500 flowering trees, shrubs, and herbaceous species grace the Great Smoky Mountains, more than any other national park in North America!
Are wildflowers native plants?
According to the North Carolina Extension Gardener Handbook: “Native plants are those species that evolved naturally in a region without any major change or improvement by humans. The term wildflower is often used to describe native plants, but may also refer to naturalized plants that are not indigenous to the region.”
People import exotic wildflowers and help them spread through landscape-altering activities such as mowing, farming, logging, and development. Nature—in the form of wind, floods, landslides, and fire, as well as birds, animals, and insects—also spread these alien plant species!
Why such wildflower diversity in the Appalachians?
The Appalachian Mountains provide a unique environment that offers an incredible variety of habitats to support our diverse wildflower population. Plants settle where the environmental conditions are best suited to their survival. And here in Western North Carolina, many different wildflower species have found their “ecological niche.”
Temperature and moisture. A wide range in elevation offers wildflowers a variety of temperatures and moisture levels. The Blue Ridge Parkway at its lowest point is 649 feet above sea level at the James River Visitor Center in Virginia and ascends to 6,684 feet at Mt. Mitchell in North Carolina—the highest point east of the Mississippi. This dramatic change in elevation creates several different climate zones ranging from warm to cool. Temperatures can vary as much as 20ºF in relatively short distances. The lower elevations have an average of 200 frost-free days each year, while higher elevations have only 100 frost-free days! The Appalachians receive abundant annual rainfall, but only an average of 50 to 55 inches at lower elevations, in contrast to 80 to 90 inches at higher elevations.
Aspect. The direction a slope faces and its shape (concave cove, convex hillside, or ridgeline) affects the amount of sunlight, rainfall, and wind protection that wildflowers receive. North-facing slopes are shady and cooler than sunnier south- and west-oriented slopes. A shady cove nestled between two mountains is moist, and cool, while a ridge exposed to the sun is hot and dry.
Soil. Soil conditions also influence which wildflowers take root. Sandstone and acidic bedrock are the predominant soil types in the southern Appalachians, but there are also areas of less acidic limestone soils rich in calcium. Evergreen and deciduous woodlands generate nutrient-rich organic matter on forest floors that supports many wildflowers.
Wildflower shows for all seasons
These environmental conditions not only determine where specific wildflower species thrive, they also determine when. Witch hazel (Hamamelis virginiana), a native flowering understory tree, blooms in winter to late fall and into January. Skunk cabbage (Symplocarpus foetidus) begins flowering in January. The main wildflower shows debut in mid-March at lower elevations and in mid-May at higher elevations. Native flowering trees and shrubs (dogwood (Cornus florida), redbud (Cercis canadensis), rhododendrons (Rhododendron catawbiense and R. maximum), and flame azalea (Rhododendron austrinum) take center stage in April, May, and June. Summer brings ironweed (Vernonia noveboracensis), jewelweed (Impatiens capensis), Joe-Pye weed (Eutrochium fistulosum), and black-eyed Susans (Rudbeckia hirta) to roadsides and meadows. The final curtain call that signals season’s end comes late-October to mid-November when goldenrods (Solidago spp.) and asters (Aster spp.) abound.
Fernleaved phacelia (Phacelia bipinnatifida) germinates in fall to provide a leafy-green winter carpet before early spring flowering, while most wildflowers don’t leaf out until spring.
Ephemerals, like Dutchman’s breeches (Dicentra cucullaria) and trillium (Trillium spp.), emerge in early spring well before trees leaf out and when they can take full advantage of sunlight reaching the forest floor. They flower, fruit, and die back all within a short two-month period. By May or June, the ephemerals have no leaves, stems, or above ground structures to signal the hiker of their existence. They go dormant and disappear below ground until the next spring.
Wherever you hike or drive in the Appalachians, you’ll find the wildflower display changes day to day and mile to mile. These jewels of the mountains await your discovery.
Article written by Beth Leonard, Extension Master GardenerSM Volunteer.
Stay tuned
Wildflowers Part II outlines identification characteristics and conservation efforts.
Wildflowers Part III describes a few of the most common southern Appalachian wildflowers.
Wildflowers Part IV discusses gardening with wildflowers.
Learn more
NC State Extension Plants
Photographs and searchable lists of wildflowers by common and scientific names.
https://plants.ces.ncsu.edu/plants/category/wildflowers/4/?category=wildflowers&s=common_name
North Carolina Extension Gardener Handbook
Chapter 10 Herbaceous Ornamentals, Section IX. Wildflowers
https://content.ces.ncsu.edu/extension-gardener-handbook/10-herbaceous-ornamentals#section_heading_9171