Asclepias fascicularis aka Mexican Milkweed

Asclepias fascicularis also goes by the name Mexican milkweed. It belongs to Apocynaceae, the dogbane family. This herbaceous perennial has soft stems and lives for years. It comes from the western United States and northern Baja California. Its range spans California, Oregon, Washington, Idaho, Nevada, and Utah. It grows on plains and in hills and valleys. It lives on both moist and dry ground. It also grows along roads and on waste land. Its home range has a temperate climate. This includes places with a Mediterranean climate.

The plant forms an upright clump of thin stems. These often branch from a thick, woody rootstock. The listed garden height is about 2.6 feet [0.8 metres]. Its spread reaches about 1.3 feet [0.4 metres]. A broader account gives heights of 1.3–3.3 feet [0.4–1 metre]. The plant grows fast. Bees, butterflies, moths, and other insects pollinate its flowers. This means they carry pollen between flowers. It draws wildlife, which makes it useful in wildlife gardens. The supplied species account gives no bloom season. It gives no fruit details either.

Choose a sunny site where soil drains well. This milkweed does not grow in shade. It grows in sand or loam, even with few soil nutrients. The soil can be mildly acid, neutral, or mildly alkaline. It grows in dry or moist soil and withstands drought. Hot summers suit it, with most rain in cooler months. PFAF lists USDA zones 7–10. It may need winter shelter outside places with Mediterranean climates. Winter mulch can help, but remove it before spring growth. Mulch left over new shoots can lead to more slug damage.

Grow more plants from seed or by spring division. Sow fresh seed in autumn, or sow in late winter. Stored seed may need two to three weeks of cold treatment. Seedlings may take one to three months to emerge. Guard young plants from slugs. Give them shelter through their first winter. Take care when you divide plants, as roots dislike disturbance.

PFAF lists cooked young flowers and leaves as traditional foods. This does not show that raw plants are safe. The milky sap holds toxic cardenolides. Drying does not remove this danger. Treat these reported food uses with great caution. Latex from the leaves and stems can supply rubber. PFAF lists no known medicinal use.