The Heat-Loving Butterfly Magnet: Discover Green Antelopehorn / Spider Milkweed (Asclepias viridis)

Famed for drawing flocks of monarchs and native butterflies with its striking greenish-white flower umbels, Green Antelopehorn (Asclepias viridis)—also widely known as Spider Milkweed or Green Milkweed—is a rugged southern native that handles scorching summer heat and drought with absolute ease. Standing at a compact 14 inches tall with unique curved seed pods and vibrant foliage, this tough perennial is an essential waystation for migrating butterflies and a fantastic addition to sunny southern or drought-tolerant gardens. (Note: Cannot ship to HI).

Plant Profile at a Glance

• Botanical Name: Asclepias viridis (Green Antelopehorn / Spider Milkweed / Green Milkweed)
• Plant Type: Herbaceous Perennial / US Native Wildflower
• Mature Height: 14 inches tall (compact, robust growth habit)
• Bloom Season: Late spring
• Sun Exposure: Full sun to part sun
• Soil Requirements: Exceptionally heat and drought tolerant; thrives in poor or well-draining soils with occasional watering
• Hardiness Zones: USDA Zones 5–11
• Wildlife Value: Premier nectar and larval source for monarchs and butterflies; highly attractive to native bees; deer and rabbit resistant

A Fascinating Folklore of Horns, Spiders, and Healing

Spider Milkweed carries a rich and storied background:

• The Antelopehorn and Spider Names: Its distinctive, curved green seed pods earned it the common moniker “Green Antelopehorn,” while the abundant white crab spiders that frequently camouflage themselves within its blooms gave rise to the classic name “Spider Milkweed.”
• The Linnaean Legacy: In 1753, legendary botanist Carl Linnaeus formally established the genus name Asclepias—named after Asclepios, the ancient Greek god of medicine and healing, honoring the plant’s historical medicinal uses.
• The Ultimate Butterfly Shield: While its leaves and milky sap contain natural toxins that deter grazing animals, monarch caterpillars and butterflies are entirely immune, storing the plant’s defense compounds within their own bodies to ward off predators.

Garden Performance and Landscape Uses

• The Southern Champion: Native primarily to the southern United States and the Texas plains, this milkweed is uniquely adapted to endure intense heat and dry spells where other perennials might falter.
• Low-Growing Elegance: Reaching just 14 inches in height, it fits comfortably into front-border placements, rock gardens, and naturalized dry meadows.

Growing and Care Tips

1. Direct Sowing (Crucial Step): Like most milkweeds, Spider Milkweed develops a deep taproot and strongly resents root disturbance, making direct sowing far superior to transplanting. Direct-sow seeds in late fall just below the soil surface, or cold-stratify spring-planted seeds in moist sand in the refrigerator for 30 days.
2. Moisture & Heat: Water young seedlings until established. Once mature, plants tolerate drought exceptionally well, though they will appreciate occasional deep watering during prolonged dry spells.
3. Seed Saving: Keep a close eye on the 3–4 inch seed pods as they mature in late summer. Harvest them right before they split open and release their silky fluff into the wind, then dry indoors and clean the seeds for storage.

Bring One Home

Ready to invite flocks of butterflies to your garden with a heat-loving, compact native milkweed steeped in folklore and southern resilience? Our nursery-grown Spider Milkweed plants are carefully cultivated and ready to thrive. Scan the QR code right on your plant pot to access complete care instructions, light and water requirements, and our full botanical catalog directly on the RKS Botanicals website!