Throughout the years, Asclepias viridis or green milkweed has acquired several common names such as spider milkweed, American silkweed, silken cissy, and white Indian hemp. It is a perennial herb native to the southeast and south-central United States. The green flowers bloom off and on during their growth from late spring to middle summer and like other milkweeds, produce milky latex sap when cut. When trying to grow green milkweed from seed, you must first cold moist stratify them for 14-30 days then soak them overnight in water to enhance germination to greater than 60 percent. June and July are the best months for seed collection.
Green milkweed can be found growing in zones 5 to 9 in dry areas, prairies, pastures, glades, ditches, and disturbed ground. Preferring full to partial sun, it is often found in cottage and butterfly gardens because their showy flower heads in the summer add interest. They adapt to various rich or poor soil environments such as sand, loam, chalky, clay and acidic. At Noxubee Wildlife Refuge in Starkville, Mississippi, the green milkweed grows in different soil types in several locations. You can see it not only in areas representing distinct prairie influence but also in marl areas of clay over chalk, creating an acidic situation. However, when hiking in Kentwood, Louisiana, you will see green milkweed thriving in total sand. The most suitable soil is slightly acidic, well drained, and other areas with little vegetative competition. The roots are moisture loving but do not like standing water. Both Malcolm Vidrine and Charles Allen (two men who have many years of experience growing them) have warned me that this particular species of milkweed can be finicky about being transplanted and that many may die. Thus, the gardening challenge of can I grow this?
I urge you to accept the challenge and try it! Not only is the green milkweed flower attractive but it is an excellent food source for pollinators. Xerces Society reports it is of special value to native bees, bumble bees, and honeybees plus supports Conservation Biological Control. Milkweed is the host plant for Monarch and Queen butterfly species therefore the females will lay their eggs on the leaves and the caterpillars will eat them. An intricate intertwined myriad of bugs visits the interesting milkweed ecosystem such as aphids, flower flies, lacewings, ladybugs, beetles, true bugs, wasps, and butterflies. The most seen beetle found on green milkweed is the red longhorn, Tetraopes tetrophthalmus, which prefers to nibble the tender end tips of the leaves. The Giant Milkweed Bug, Oncopeltus fasciatus, is a true bug commonly found on the flowers and seed pods because they pierce and suck juices. Milkweed serves a double purpose of providing pollen and nectar for the pollinators then the foliage is a host plant—without it, monarch and queen caterpillars cannot survive. The presence of green milkweed plays a crucial part in helping spring monarchs have a successful enough migration to sustain the overall population. When adding this plant to your garden, you will be amazed at the new wildlife you will see.