Perennial
Asclepias tuberosa. Butterfly Bush Milkweed seeds, sometimes called Orange Milkweed, is a hearty perennial intensely attractive to butterflies and other beneficial garden insects. It is highly drought resistant, so useful for xeriscaping. Unlike other members of the Milkweed family, Butterfly Weed does not issue a milky sap when broken. Waxy green stems to 70cm (27") tall are topped by vivid orange flower clusters. Grown in small clusters, this plant attracts butterflies like no other, even in urban gardens. Flowers are followed by exotic looking fruits that release easy-to-harvest seeds. All milkweeds are useful, nectar rich food plants for butterflies, including the Monarch butterfly.
West Coast Seeds Butterfly Bush Milkweed Seeds, Per Package
Starting
Barely cover the small seeds using sterilized seed starting mix. Space transplants 30-60cm (12-24″) apart.
Timing
Sow indoors 6-8 weeks before the last frost date and transplant towards late spring. Milkweed requires cold stratification to break dormancy. Sow the seeds in damp soil in 18 cell plug inserts and place in a refrigerator for two weeks or place outside in early spring. Transplant when the seedlings are 2 inches (5cm) tall. Optimal soil temperature for germination: 10-25°C (50-75°F). Seeds should sprout in 7-35 days.
We have had success direct sowing A. tuberosa in March, with blooms the first year. In our experience, A. speciosa returns with vigour in the second year and begins blooming by June here on the west coast.
Growing
For many years several Asclepias species were listed as invasive weeds because of their sometimes aggressive spreading by underground rhizomes and their giant, dandelion-like seeds. The seeds emerge from very conspicuous pods which are easily removed before they dry and crack. As the population of wild Asclepias diminished, so did the populations of many butterflies that depend on them as food and nursery plants (including the endangered Monarch). Now that they have been de-listed, we encourage home gardeners to grow them with the advance knowledge that they can spread. Try growing them in a large container like a half barrel, and be conscious of the seed pods as they develop. In short, please be responsible with Asclepias species.
Note: All parts of the plant are harmful if eaten. Flowers are not edible.
