Chrysogonum is a plant genus that is part of the Asteraceae family. It contains just one species, Chrysogonum virginianum, which is commonly referred to as the green-and-gold or goldenstar plant. The perennial herb is native to the southeastern United States and features star-shaped yellow flowers that generally bloom from the early spring to late summer. Its flowers sit atop hairy stems and are surrounded by a dense foliage of oval-shaped, hairy green leaves. Chrysogonum is typically used as ground cover in open areas or as borders along pathways.
Most varieties of Chrysogonum virginianum are creeping, low-lying plants that extend long branching stems, called stolons, into the surrounding area and take root above ground. There are a few varieties that are a bit more upright, especially the northern most variety of the species. These typically are one foot (about 30 cm) tall. The stolons extending from both the creeping and upright varieties originate from a rhizome, which is the main stem of the plant and is typically located underground.
Since the chrysogonum is a fast-spreading plant, it should be pruned regularly so that it grows in the area in which it was planted. This is especially true if the plant is used as edging material for walkways or as the backdrop for rock gardens. In most cases, if allowed to spread, chrysogonum will grow into thick ground cover that may overwhelm neighboring plants.
Generally, the plant grows well without much effort on the part of the gardener. It does require an acidic soil that is moist and well draining. The area in which the plant is located should be partially shaded from the sun. Full sunlight is generally not harmful, as long as the exposure isn't for more than a few hours each day. Climate wise, the perennial herb thrives in USDA Hardiness Zones five to eight.
To prolong the life of the chrysogonum, it is recommended to divide or transplant it every other year. Usually, division is the best propagation method and it is generally done in the fall or late winter. Softwood cuttings is also a viable method and is typically done in the late spring. Propagation by seeds is not as easy as the other methods since it requires a soil temperature of 70°F (about 21°C) to germinate. Seeds are mature when the heads have darkened, which usually takes two to three weeks after the yellow flowers drop. After collecting the seeds, they should be placed in sealed containers and stored in a refrigerator.