Tall Green Milkweed (Asclepias hirtella) Quick Facts:
Host and nectar plant to Monarch Butterflies
Native in Central US
Hardy in zones 4-9
Prefers full sun, may tolerate partial shade
Needs well-drained soil, dry to medium moisture
White flowers with green tinges bloom mid summer
Grows up to 4 feet tall
Space 1 1/2 – 2 feet apart
Seeds need 30 day cold stratification or sow in fall/winter
Tall Green Milkweed Characteristics
The Tall Green Milkweed has 2-10 floral clusters per stem and each of these umbels is made of 30-100 green-tinged white flowers, which is more blossoms per plant than most of the milkweeds.
This milkweed blooms in mid-summer (June, July, and August), and its flowers are a nectar source for many butterflies, including the Monarch.
Long, lance-shaped leaves enhance the Tall Green Milkweed and are attractive to Monarchs for laying eggs. Emerging caterpillars then feast on the plentiful foliage.
Asclepias hirtella grows up to four feet tall. It is hardy in USDA zones 4-9 and is native in the central/eastern US and eastern Canada. It loves full sun and hot, dry soil (think sandy or gravelly loam) best, but will also perform in well-drained moist areas and partial shade. If starting from the Tall Green Milkweed seeds, plant in a location that allows for sun, drainage, and growth.
The Tall Green Milkweed has a long, vigorous tap root that makes it drought tolerant. Transplanting is stressful to the milkweed if the long tap root is established. The plant will self-seed, but is not considered invasive.
Starting from Seeds:
Tall Green Milkweed seeds require 30 days of cold stratification to break dormancy or they may be fall or winter sown. After stratification, plant the seeds up to 1/8” deep in the soil. Keep moist. If starting indoors, transplant after your last frost. Space the plants 18-24 inches apart.
Can You See Tall Green Milkweed in Your Garden?
With its bountiful blooms, the Tall Green Milkweed is a perfect addition to your butterfly garden. As a Monarch host plant and nectar plant to many, butterflies will love this milkweed!