Asclepias ‘Silky Gold‘ | Silky Gold Tropical Milkweed
Asclepias ‘Silky Gold’, or Asclepias curassavica ‘Silky Gold’, commonly known as Silky Gold Tropical Milkweed or Golden Butterflyweed, is a vibrant, fast-growing perennial that adds bold color and essential ecological value to the garden. A cultivar of the South American species Asclepias curassavica, this selection features large clusters of deep golden-yellow flowers that bloom prolifically throughout the warmer months. With its upright form, narrow lance-shaped leaves, and striking blossoms, ‘Silky Gold’ stands out in borders, meadows, or wildlife-friendly plantings where it attracts Monarch butterflies and other pollinators with remarkable success.
The plant family for Asclepias curassavica is Apocynaceae (formerly placed in Asclepiadaceae, which is now a subfamily, Asclepiadoideae). This family includes many tropical and subtropical species, often with milky sap and specialized pollination systems.
Description of Asclepias ‘Silky Gold’
This herbaceous perennial grows quickly to a height of 90 to 120 cm (3 to 4 feet) and spreads about 60 to 90 cm (2 to 3 feet) wide. Its foliage is narrow and pointed, a yellow-green in color, and offers a gentle contrast to the brilliant, sun-like flowers. Each floral cluster stretches about 7.5 to 10 cm (3 to 4 inches) long and contains dozens of small, intricate blooms. The flowers exhibit the characteristic milkweed structure, with five recurved petals beneath a complex corona that shields the stamens—both parts displaying a rich golden yellow hue.
Silky Gold blooms from early summer through fall, and in warm climates, flowering may extend year-round. These blossoms are followed by elongated seed pods that release silky-tufted seeds, allowing the plant to self-sow readily in favorable conditions. The stems are tall and upright, making them suitable for cutting gardens as well as mixed perennial beds. As the common name suggests, this cultivar serves as an important larval host for Monarch caterpillars and offers a rich nectar source for adult butterflies, bees, and other beneficial insects.
Though tropical in origin, Asclepias ‘Silky Gold’ has naturalized in many parts of the southern United States. However, concerns have arisen over its potential to interfere with Monarch migration when left to grow year-round. Pruning and responsible management help mitigate this issue.
How to Grow Asclepias ‘Silky Gold’
Light
‘Silky Gold’ thrives in full sun and performs best when exposed to at least six hours of direct sunlight each day. It can tolerate partial sun but may grow lankier and produce fewer flowers in shadier conditions.
Soil
This milkweed prefers slightly sandy to loamy soils with excellent drainage. While tolerant of a range of soil textures, it dislikes soggy roots and benefits from being planted in raised beds or well-aerated ground.
Watering
Water regularly during the first growing season to help establish a deep, healthy root system. Once mature, the plant tolerates periods of dryness but will bloom more profusely with consistent moisture. Avoid overwatering, especially in heavy soils.
Fertilizing
Use a balanced, slow-release fertilizer in early spring, or apply a diluted liquid fertilizer every few weeks during active growth. Excess nutrients are not necessary for healthy blooms, so fertilize sparingly to avoid weak, leggy growth.
Pruning
Cut the plant to the ground in autumn, especially in regions where it does not go fully dormant. This reduces the risk of disrupting Monarch migration cycles, as it discourages butterflies from breeding out of season. Also, remove seed pods if you want to control its spread.
Winter Care
In USDA Zones 8 to 11, ‘Silky Gold’ may survive as a perennial with minimal protection. In colder areas, grow it in containers and move indoors before frost. Mulch heavily if overwintering outdoors in marginal zones, or treat it as an annual in cooler climates.
Propagation of Asclepias ‘Silky Gold’
‘Silky Gold’ propagates easily from seed, especially in warmer regions. Harvest mature pods when they begin to split and sow seeds directly in the garden or start them indoors in early spring. The plant also roots from softwood cuttings, though this method is less common. Be sure to wear gloves when handling sap, which is toxic and can irritate skin or eyes.
Pests and Diseases
While relatively pest-resistant, Silky Gold may occasionally attract aphids, especially during peak bloom. Rinse off minor infestations with a blast of water or use insecticidal soap for larger outbreaks. Rabbits typically avoid this plant due to its bitter, milky sap. As with all milkweeds, take care to avoid eye contact with the sap, which can cause serious irritation.
Ecological Role of Asclepias ‘Silky Gold’
Silky Gold Tropical Milkweed is more than a colorful addition to the garden—it’s a critical support species for Monarch butterflies. Its tender leaves provide essential nourishment for Monarch caterpillars, while its nectar-rich flowers support adult butterflies and other pollinators. However, ongoing debate surrounds the role of Asclepias curassavica in monarch conservation. In mild climates where the plant does not die back, year-round availability of foliage may encourage breeding at the wrong time of year, increasing the risk of spreading the parasite Ophryocystis elektroscirrha (OE). Cutting back plants in the fall addresses this issue and encourages responsible habitat stewardship.
In California, conservation concerns led to Asclepias curassavica being listed as a B-rated noxious weed in 2022—not due to invasive growth, but because of its potential impact on Monarch migration patterns. Despite this, many scientists argue the evidence remains inconclusive, and the plant continues to be a popular and effective pollinator attractor in much of the U.S. The key lies in responsible cultivation and seasonal management.
Historical and Botanical Background
Asclepias curassavica is native to South America, particularly regions around Curaçao, as referenced by the specific epithet “curassavica.” It now grows in tropical and subtropical zones worldwide. The genus Asclepias honors Asclepius, the Greek god of healing, reflecting milkweed’s traditional medicinal uses. Over the years, it has gained many local names including Bloodflower, Scarlet Milkweed, Mexican Butterflyweed, and Wild Ipecac.
Asclepias ‘Silky Gold’ is a refined, ornamental cultivar bred for its vivid golden flowers and ease of growth. While it is not native to North America, its ecological value and aesthetic beauty make it a garden favorite—especially for those seeking to create butterfly-friendly landscapes with a long bloom season and dramatic visual appeal.
