Asclepias speciosa aka Greek Milkweed

Asclepias speciosa, or showy milkweed, has non-woody stems and lives for years. Its plant family is Apocynaceae, the dogbane family. It is native to western and central Canada and the United States. It grows on dry slopes and by roads. It also grows in open woods, along streams, and in prairies. In prairies, it may grow in moist sand or loam.

Plants grow 2–4 feet (0.6–1.2 metres) tall. They have stout stems that stand upright. The listed garden spread is about 1.5 feet (0.46 metres). Thick stems hold broad, oval leaves with clear veins. The soft leaves are gray-green or blue-green. They can reach about 0.7 feet (0.2 metres) long. White down coats new shoots and flower stems. Stems and leaves give off milky sap when cut or bruised.

The flowers have a scent and grow in round groups. These groups sit near the upper leaves. Each can span about 0.25 feet (0.08 metres). The blooms range from pale pink to purple-pink. Each has a star-like shape, small hoods, and curled horns. Missouri Botanical Garden lists May to June as bloom time. Chicago Botanic Garden lists July and August as well. Rough, hairy pods form after the flowers. They split open when ripe. The blooms draw butterflies, as well as hummingbirds. Monarch caterpillars eat the leaves, which help protect them from birds.

Grow this plant in full sun with soil that drains well. It suits dry ground or soil with a fair amount of moisture. It can grow in poor soil with gravel. Once plants take root, they cope with drought. Deer tend to leave them alone. Both gardens list USDA hardiness zones 3–9. Seeds make it easy to grow new plants. Deep taproots make plants hard to move once they take root. Plants may spread by seed unless you remove pods before they open. Use them in borders, rock gardens, or meadows. They also suit areas for native plants. Their loose, weedy look may not suit a formal bed. Reports list no major pest or disease problems. Aphids can cause harm. But steps to control them may harm helpful insects too.

Plants For A Future lists food uses for several parts. These are cooked young shoots, leaves, flowers, and young pods. Its claims about seeds as food conflict, so their safety remains unclear. It also lists past uses for roots and latex. These records do not prove that medical use is safe or works. Chicago Botanic Garden says the sap is mildly toxic. Reports also warn that eating large amounts can cause poisoning. Stem bark yields tough fibre for twine, coarse cloth, and paper.