How to Grow and Care for Butterfly Weed

Bee on yellow butterfly weed

Butterfly weed is a milkweed plant that attracts butterflies to the garden with its clusters of bright orange-to-yellow blooms rich with nectar and pollen. This clump-forming perennial grows two feet tall from tuberous roots with glossy green, lance-shaped leaves. It requires at least eight hours of full sun and well-draining soil and can handle a wide range of temperatures, from freezing to high heat.

Unlike other milkweeds, butterfly weed does not have caustic milky sap, but it is still considered mildly toxic to humans and animals.

Common Name Butterfly weed, butterfly milkweed, pleurisy root, orange milkweed
Botanical Name Asclepias tuberosa
Family Asclepiadaceae
Plant type Herbaceous, perennial
Mature size 1–2 ft. tall, 12-18 in. wide
Sun exposure Full
Soil type Dry, well-drained
Soil pH Acidic, neutral
Bloom time Summer
Flower color  Orange, yellow
Hardiness zones 3–9 (USDA)
Native area North America
Toxicity Mildly toxic to animals and humans

Butterfly Weed Care

Plant butterfly weed in late spring after the soil warms. Do not expect it to bloom the first year; flowering may take three years. Blooms last about two months, from late spring until late summer. A. tuberosa produces seed pods that release silky-tailed seeds to disperse on the wind.

Here are the main care requirements for growing butterfly weed:

  • Grow butterfly weed in a sunny spot with well-draining soil.
  • Sow seeds directly in the garden—butterfly weed does not require much tending to to thrive,
  • Water a new plant well during its first growing season, but the plant will prosper even in drought-like conditions when established.
  • Its seed pods will turn brown towards the end of the growing season (early autumn) and will burst to spread seeds throughout your garden, which emerge as new volunteer plants the following spring.
  • While the plant can take up to three years to fully mature and produce flowers, its blooms will gradually grow denser with each season that passes.

Butterfly weed is a beneficial plant that monarch butterflies need to survive, and it’s native to most of the United States. However, a similar species, tropical milkweed (Asclepias curassavica), has been linked to migration pattern disruption. Steer clear of tropical milkweed. Instead, plant milkweed species that are native in your state.

Two orange and black butterflies on orange butterfly weed

Light

Choose a spot in your garden that boasts bright sunlight daily, as this plant loves to soak up the rays. Full sun is your best bet.

Soil

Butterfly weed can prosper in various soil conditions and compositions, from sand to gravel, and it generally prefers a neutral to slightly acidic pH.

Water

Until new plants start to show mature growth, you should maintain a moist soil environment for butterfly weed—about one inch of water per week for its first year. Once the plant is established, you can dial back to watering only occasionally.

Temperature and Humidity

Butterfly weed thrives in various temperature and humidity settings, growing well in zones 3 to 9. Generally, the plant emerges in late spring, hitting its peak bloom during the warmer summer months and drying on the stem throughout the autumn and winter.

It handles high humidity and arid climates equally well, provided it gets adequate soil moisture.

Fertilizer

Butterfly weed is a low-maintenance plant that does not require any additional fertilization. Doing so can harm the plant, making it excessively leggy and reducing blooms.

Types of Butterfly Weed

There are several named cultivars of this plant. Most varieties, as well as the native species, are orange. But some popular varieties offer color variations:

  • ‘Hello Yellow’ is a variety with bright yellow flowers.
  • ‘Gay Butterflies’ has decidedly reddish flowers.
  • ‘Western Gold Mix’ has golden-orange flowers and is bred primarily for the alkaline soils of the western United States.