milkweed plant seeds Asclepias speciosa, Showy Milkweed

We are happy to offer one of the showiest milkweeds, with a wide range in California, always a pleasure to see. Its blossoms are of a soft, rich pink and deliciously fragrant. Its 5" long Its fuzzy leaves are often covered with the caterpillars of Monarch butterflies in summer.

Xerces Native Milkweed Planting and Establishment Guide for the Western United States

Ecological Function

The native milkweeds are famous for being a host plant for the monarch butterfly. The butterfly lays its eggs on milkweed plants and only on milkweed plants, which supply the nutrients the egg needs as it turns into a caterpillar. Research on the reasons trend towards monarch extinction always lists the absence of only native  as a major factor in successful monarch reproduction. Can be seen in summer covered with the green caterpillars that will become monarch butterflies. It grows 2-4' tall in full sun and can handle some shade. Do not plant non-native milkweeds; they  can be a serious problem.

Growing Procedures

There are 75-100 seeds per packet, enough for at least 25 to 30 plants. Milkweeds need cold-stratification, which simulates cold weather. Place seed on damp paper towel. Put the towel and the seed in a plastic bag and place in a refrigerator. This is "cold-stratification." After a month, sow the seeds in a warm greenhouse. The seeds will appreciate some warmth to germinate. It goes dormant in the late summer. It spreads through underground rhizomes.

Tips

We recommend using species that grow in your region, if possible. Coastal gardeners should think twice before planting milkweeds, which may not have grown there historically. It may create problems to draw migratory species out of their regular patterns. For example, some species may not have resistance to the fungi stimulated by fog. The caterpillars that will develop on that plant may not survive, thereby "wasting" the eggs of that species.

Give them full sun and only water occasionally once they are established. These plants go dormant in late summer and fall. They spread through rhizomes into large clumps, and make a beautiful display.

There are 75-100 seeds per packet, enough for 30 to 40 plants.