More Information About Asclepias
Asclepias plants are popular perennial flowering plants that attract butterflies with their brightly colored flower clusters, hence the common names Butterfly weed and Butterfly flower. The flowers, leaves, and stems of this perennial wildflower are toxic, but not to butterflies or their larvae. Butterflies and other herbivorous insects that ingest asclepias nectar or leaves store the toxins in their bodies becoming toxic to any birds that subsequently snack on them. Monarch butterfly larvae feed almost exclusively on Asclepias leaves.
The brightly colored flowers are also popular with hummingbirds. We have collected a few special asclepias selections hoping that gardeners will broaden their botanical horizons with a variety of butterfly milkweeds. Many Asclepias species are North Carolina native plants for those of you inclined to favor them.
Asclepias is drought-tolerant and prefers full sun and well-drained, somewhat dry soil. It is a tough, low maintenance plants which make it perfect for rain gardens. Some milkweed plants are also salt tolerant.
Broken stems will produce a milky latex sap that is a skin irritant to some so take care when pruning milkweed. The attractive, long-lasting flowers of Asclepias are followed in the late summer by spindle shaped seed pods that split open to release dandelion-like seeds attached to a fibrous parachute.
Asclepias is in the dogbane family and is a botanical cousin of mandevilla, amsonia, and vinca.
How to Grow and Care for Asclepias (Milkweed)
Where to Plant – Most Asclepias species are native to North America and can be planted in most typical garden conditions provided there is adequate sun and proper drainage.
When to Plant – Mid to late summer is the best time to plant, but Asclepias can be planted in any season once the danger of frost is over.
How Much Sun? – Milkweed does best with at least 6 hours of full sun for the best flowers.
Type of Soil – Good drainage is the key. Many milkweeds are salt and drought-tolerant and can be grown even in poor soils. Crown rot can occur in overly wet, poorly drained soils or if planted too deep. Many species of Asclepias prefer slightly acidic soil.
How Much Water? – Adequate water is important until the plant has established roots. Keep the area moist but not too soggy. Again, good drainage is key. Once established, water moderately. Asclepias incarnata (Swamp Milkweed) prefers moist to soggy soils but can fare well in typical garden soils.
Fertilizer – In the garden, supplemental fertilizer is typically not necessary.
Pests & Diseases – Milkweeds are mostly pest free but can be susceptible to aphids. Crown rot can occur if planted too deeply or over-watered in poorly drained soils. Milkweed is deer and rabbit resistant.
Blooming – Asclepias species bloom throughout the spring and summer. Longer days are required to break dormancy.
Toxicity – Asclepias is poisonous to livestock so avoid planting in or around pastures. While Asclepias is not dangerously toxic to humans, the sap can cause skin irritation for some so be sure to wear appropriate gloves when pruning.
Here are just a few of the possible companion plants to get you started. Visit our collection of butterfly attracting plants for a comprehensive list.