Chrysogonum virginianum L. [kris-OG-oh-num, vir-jin-ee-AN-um], also synonymously known as Chrysogonum australe is a perennial plant known for its ornamental value as a ground cover.
This is in reference to the beautiful bright daisy-like flowers growing strikingly against vivid green foliage.
These flowers are the reference for various common names including golden-knee, green and gold, and goldenstar.
A part of the Asteraceae or composite flower family, along with fleabane daisy and Cosmos.
This particular species of the genus is native to North America. You will find it across the eastern United States.
They grow lush across New York, Rhode Island, Louisiana, and northwestern Florida.
The scientific name of the genus is a combination of Greek word chrysos, which means gold.
The word gonu is a reference to the stem joints.
As for the specific epithet, it means “of Virginia” – a reference to its location.
Chrysogonum Virginianum Plant Care
Size & Growth
This perennial or semi-evergreen native plant grows strong in low mats.
When provided with all the right growing conditions, it spreads rapidly through stolons or rhizomes.
As you would expect, it is a great flowering ground cover.
It may grow 3”-4” inches tall with a spread 18” inches wide or more.
The foliage has hairy, spooned green leaves.
Each leaf is about 3” inches long, ovate and toothed.
The bright color green of these leaves creates a great contrast against the yellow flowers.
Flowering and Fragrance
The Chrysogonum is known to produce a plethora of bright yellow daisy-like flowers.
The bloom time of golden-knee plants lasts from early spring to late spring but is prolonged with deadhead until fall arrives.
The bloom color is typically a bright yellow.
Each flower is about 1.5” inches in diameter, borne on flower stems.
These stems originate in leaf axils and grow above the foliage.
A stem can reach a height of 8”-10” inches.
The flower on top has 5 petals each, which are rounded and slightly notched.
At the center of each flower, you’ll find a tuft of yellow disk flowers.
While they aren’t fragrant, these flowers certainly put on a great show.
Light & Temperature
Hardy to USDA Hardiness Zones 5 through 9, green and gold plant species prefer full shade to part shade.
Some varieties of this species may tolerate the full sun but only when it’s grown in rich and consistently moist soils.
Even then, locations dappled in partial shade are better.
The heat of the summer in mentioned USDA zones is when the Chrysogonum blooms their best.
Watering and Feeding
Medium to wet soils is the preference of these rhizomatous plant types.
Regular watering during summers in hot climes is required for the plant to thrive.
Don’t overwater in the colder months.
However, if your goldenstar plants are situated in overly sunny and windy areas, you need to maintain consistent moisture or the plant may dry up and affect other plants in its proximity along with it.
There is no compulsory need for fertilizers but the plant may benefit from it.
If you choose to feed the plant, choose a slow-release, organic formula and add it to the top inch layer when you transplant them.
Or amend the soil’s fertility in the spring and summer by sprinkling the feed.
Soil & Transplanting
When it comes to soil, the plant is partial to neutral or acidic soil.
Average soils with decent drainage are optimal.
Even though the plant likes good soil moisture, some drainage is required to prevent root rot.
Transplanting for the purpose of repotting is usually not required with golden-knees.
These grow as ground covers but are repotted when the need arises for propagation by division.
The process is pretty easy as rhizomes are easy to extract and replant.
Grooming and Maintenance
Considering it is a low-maintenance plant, there is no need to worry about constant pruning.
Deadheading may be required to prevent the self-seeding process.
How To Propagate Golden-Knee Plants
Not only are these plants fast growers, but they also self-seed.
Collect the seeds and grow them yourself.
Come late spring, collect the seeds found around the base of the plant.
Sow them in a potting mix at a temperature between 70° to 75° degrees Fahrenheit (21° – 24° C).
The germination may begin within three weeks.
Propagation by the division of the crown is also possible but softwood cuttings are the best option.
If your goldenstar variety produces stolons, cut and dig them up from mature plants.
Transplant directly elsewhere and you are good to go.
Golden-Knee Plant Pest or Diseases
Problems such as root rot and drying is avoided by choosing a location with part sun or full shade and moist soil.
If you get these right, issues are rare.
There may be some susceptibility to snails and slugs in the springtime when new growth emerges.
Fortunately, these are amendable.
Powdery mildew or downy mildew may appear but it’s possible to treat them.
Chrysogonum Virginianum Plant Uses
It’s nativity to woodland areas, these deer-resistant plants do great in woodland gardens.
They are used for edging native plant gardens, woodland paths, and other naturalized areas.
The bright yellow flowers are also great in rock gardens, shade gardens, and border fronts.
Chrysogonum virginianum var. brevistolon pairs well with Virginia bluebells, providing beautiful garden interest.