Solidago altissima

Solidago altissima, or Canadian Goldenrod, is a herbaceous perennial wildflower and one of the many species of the genus Solidago and is the state wildflower of South Carolina. It has a central stem, or sometimes stem clusters, 2 to 6 feet tall supporting masses of small, dark yellow, plume-like flowers. One plant can produce as many as 1500 small yellow flower heads in a large conical array. Because most of the other goldenrod species have small, yellow, blossoms, they are often confused with each other.

Canadian Goldenrod produces alleleopathic compounds that suppress the growth of other plants and, thus, it can become weedy. Although goldenrod is often blamed for hay fever because it is in bloom during that season, ragweed is the actual culprit.  

Canadian Goldenrod does well in dry soil and sites that have been disturbed by humans. It prefers full to partial sun, and average moisture levels. This plant will tolerate some drought, in which case it will probably drop some of its lower leaves. It also tolerates a variety of soils, seeming to prefer a heavier soil with some clay content. It is extremely rhizomatous and not recommended for smaller planting areas. The root system is fibrous, producing creeping rhizomes that cause the plants to cluster, sometimes forming dense colonies.

Insects, Diseases, and Other Problems: During the fall, powdery mildew occasionally attacks the leaves. This plant is deer resistant.