Asclepias rubra aka Red Milkweed

Asclepias rubra is a perennial wildflower called red milkweed. Red silkweed is another name for this species. It belongs to the dogbane family, Apocynaceae. Its native range spans the eastern and southern United States. It grows from New Jersey south to Florida, reaching Texas. Wild plants grow in sandhills, swamps, and wet pine savannas. In North Carolina, it occurs in the sandhills.

Plants grow upright, reaching 2–3 feet (0.61–0.91 metres) tall. Some plants reach only 1.5 feet (0.46 metres). Their spread is about 0.83–1 foot (0.25–0.30 metres). Growth proceeds at a medium rate. Round, green stems release milky sap when broken. The green, leathery leaves grow in opposite pairs. They range from egg-shaped to lanceolate, with pointed tips. Their bases may be rounded or heart-shaped. Short stalks, or none, join them to the stems. Fine hairs line the otherwise smooth leaf edges.

Small pink to lavender flowers open in June and July. Clusters form at stem tips and beside the leaves. Each flower has a tubular, star-like form. Bees and other pollinators visit the blooms. Monarch caterpillars feed on the plant. Smooth seed pods follow, with a display from July through September. These reach 0.25–0.42 feet (0.08–0.13 metres) long. Ripe pods split and release seeds with silky white hairs. Wind carries these seeds away. Collect pods before they split when saving seed.

Grow red milkweed in sun or partial shade. It needs acidic soil that stays moist to wet. Sandy and loamy soils suit it, and it tolerates occasional flooding. It grows in USDA zones 6–9. Use it beside ponds, along streams, or in bog gardens. Rain gardens and butterfly gardens also suit its needs. Its narrow form fits small spaces, borders, and containers. Seed provides a means of propagation. Avoid disturbing its roots; set young plants in their final place.

NC State reports no major disease issues. Aphids, milkweed beetles, and leaf-feeding caterpillars seldom cause serious trouble. Large and small milkweed bugs can damage the pods. The sap can irritate skin and eyes. Eating large amounts can cause gut upset, weakness, and confusion. The plant also poses risks to cats, dogs, and horses. PFAF lists cooked buds, leaves, shoots, and young pods as edible. These reports do not remove the plant's documented poisoning risks.