Butterfly Weed (Asclepias tuberosa)

Butterfly Milkweed, Butterfly Weed, Chieger Flower, Chiggerflower, Common Butterfly-weed, Indian Paintbrush, Milkweed, Pleurisy Root

Butterfly weed plants (Asclepias tuberosa) are trouble-free North American natives that produce umbels of bright orange, yellow, or red blooms all summer long. Butterfly weed is appropriately named, as the nectar and pollen rich flowers attract hummingbirds and hordes of butterflies, bees, and other beneficial insects throughout the blooming season. Do you want to know more about how to grow butterfly weed? Read on.

I. Appearance and Characteristics 

Asclepias tuberosa, commonly known as butterfly weed, is a species of milkweed native to eastern and southwestern North America. It is commonly known as butterfly weed because of the butterflies that are attracted to the plant by its color and its copious production of nectar.

It is a perennial plant growing to 0.3–1 m (1–3+1⁄2 ft) tall. The leaves are spirally arranged, lanceolate, 3–12 cm (1+1⁄4–4+3⁄4 in) long, and 2–3 cm (3⁄4–1+1⁄4 in) broad.

From April to September, in the upper axils, 7.5 cm (3 in)–wide umbels of orange, yellow or red flowers 1.5 cm (1⁄2 in) wide appear. They each have five petals and five sepals. It is uncertain if reddish flowers are due to soil mineral content, ecotype genetic differentiation, or both. A cultivar named ‘Hello Yellow’ typically has more yellowish flowers than ordinary examples of this plant.

The fruit pod is 7.5–15 cm (3–6 in) long, containing many long-haired seeds.

The plant looks similar to the lanceolate milkweed (Asclepias lanceolata), but is uniquely identified by the larger number of flowers, and the hairy stems that are not milky when broken. It is most commonly found in fields with dry soil.

This plant favors dry, sand or gravel soil, but has also been reported on stream margins. It requires full sun.

The plant contains toxic glycosides, alkaloids and resinoids. These can cause weakness, seizures and corneal injuries. Use of the plant is contraindicated in pregnancy, during lactation or with infants due to its toxins, which include retinoids and pregnancy.

II. How to Grow and Care

Sunlight

If possible, choose a spot in your garden that boasts lots of bright sunlight daily, as this plant loves to soak up the rays. Full sun is definitely your best bet.

Temperature and Humidity

Butterfly weed thrives in a variety of different 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.

Watering

During its first year of life (or until new plants start showing mature growth), you should maintain a moist soil environment for butterfly weed, giving it about one inch of water per week through combined rainfall and irrigation.

Once the plant appears to be well-established, you can cut back to watering it only occasionally, as it now prefers dry soil. An extensive, deep taproot helps it thrive even in dry conditions. Mature plants can do well with just monthly watering in all but the driest climates.

Soil

Butterfly weed adapts to various soil environments. The most suitable soil is slightly acidic and well-drained. If the planting soil is sticky, add some leaf mold, organic fertilizer, river sand, or a similar compound and stir evenly to improve soil texture. You can also add a little soil at the base of the plant to encourage growth. This will prevent plant lodging and provide more nutrients to the roots.

Fertilizing

Butterfly weed does not require much fertilizer, so doesn’t need to be fertilized often. After flower buds appear, a little phosphate fertilizer ensures growth during the flowering period. Apply organic fertilizer once before winter. This will increase the plant’s ability to withstand the harsh environment and survive the season. During dormancy, the physiological activities of butterfly weed will slow down or even stop. Overfertilization causes excessive accumulation of nutrients, which leads to root rot. Hence, stop fertilization after the plant enters winter dormancy.

Planting Instructions

Butterfly weed can be sown in spring, planted in flower pots or placed directly in the garden. You can keep seeded pots indoors. Sow at warmer temperatures for best results. The seeding depth is about 2.5 cm. Press the soil slightly, so that the soil and the seed make firm contact. After sowing, water the seeds thoroughly. Generally, they will germinate after two weeks with a germination rate of about 80-90%.

When the seeds in the pot germinate with 2-3 pairs of leaves, they can be transplanted into the ground. When transplanting, keep the soil on the roots to avoid damaging the root system. Remember to water thoroughly after planting. Butterfly weed grows best in a ventilated environment, such as by a road, wall, or window. Without good ventilation, pests will appear, which can threaten the plant’s growth.

Pruning

Regularly remove infected plants and wilting leaves to keep butterfly weed healthy. If you are located in a tropical or subtropical climate, you can cut off branches in early spring to promote germination. Given the high toxicity of butterfly weed, wear gloves when handling plants to prevent poisoning. Keep butterfly weed away from children, avoid direct contact, and do not eat the plant.

Propagation

Butterfly weed often sprouts many small seedlings. In early spring, you can dig out the seedling bunch. Use a sharp clean knife to divide the root into several parts and plant them separately.

How to Grow from Seed

Typically, the easiest and most successful way to add butterfly weed to your garden is to grow it from seed. Plant fresh seeds in fall for growth the following spring, or allow any established butterfly weeds already in your garden to do the work for you.

Beginning in late summer or early fall, the plants should start to develop seed pods at the base of the pollinated blooms. If left on the stem, the pods will eventually burst and the seeds inside will be blown throughout your garden, allowing them to establish themselves in the soil in time for the following year. If you’d rather have more control over the eventual location of any new butterfly weed plants, you can remove the seed pods from the plant before they burst open and simply plant new seeds by hand instead.

If you want to start seeds indoors, the seeds need cold stratification. Here’s how to do it:

  • Place seeds in moist seed starting mix in a container.
  • Cover with a lid and leave in the refrigerator for two months.
  • Remove from the refrigerator eight weeks before last expected frost, and place in a warm spot under grow lights. Do not let seeds dry out.
  • Once the seedlings have two sets of true leaves, pot them up in potting soil, and continue to grow inside.
  • As temperatures warm outside and all danger of frost has passed, harden off seedlings for a week, then transplant in the garden.

Overwintering

Overwintering butterfly weed is a simple matter of cutting off the plant stem near ground level as soon as the plant succumbs to cold temperatures in the fall or early winter. There is no harm to leaving the plant stalks in place, though this encourages rampant self-seeding, which is usually not desired. Don’t mulch over the root crowns, as this can encourage rot.

Pests and Diseases

Common Pests and Plant Diseases

In most circumstances, butterfly weed is largely trouble-free, but it can be susceptible to root rot if it is planted in dense soil that gets too much moisture. It can also be susceptible to fungal diseases such as rust and other leaf spots, though these are usually merely cosmetic and not fatal.

The plant can be susceptible to aphid damage, which usually is controlled by lady beetles and other predator insects. The plant serves as a host plant to many butterflies, including monarchs, so expect the leaves to be eaten. Do not use pesticides on milkweed.

Common Problems 

Other than the root rot that can appear in dense, wet soils, there are only a couple of common problems with butterfly weed.

Self-Seeding

The most common issue with butterfly weed is the rampant self-seeding that happens if the seed pods aren’t removed before they burst and scatter their seeds. This can be prevented by removing the seed pods before they dry and burst open. The volunteer plants that appear due to self-seeding should be removed before they establish long tap roots.

Rabbit Damage

Butterfly weed is very attractive to feeding rabbits. Rodent repellent granules or sprays can provide some prevention, but metal fencing around the plants is the best solution.

III. Uses and Benefits 

  • Ornamental uses

The Butterfly weed is commonly used in nature gardens, in borders or in open spaces. It also looks great in stone beds. It should ideally stand proud, with no taller plants around. Asclepias tuberosa is excellent for pairing with grasses, echinacea, blue wild indigo or coppertips as these flowers at the same time. Butterfly weed also looks fabulous in pots on a terrace.

  • Medicinal uses

Native Americans and European pioneers used the boiled roots to treat diarrhea and respiratory illnesses. The young seed pods were used as food after being boiled in several changes of water. The seed pod down was spun and used to make candle wicks.

The root was once used to treat pleurisy.

Butterfly Weed (Asclepias tuberosa) Details

Common name Butterfly Milkweed, Butterfly Weed, Chieger Flower, Chiggerflower, Common Butterfly-weed, Indian Paintbrush, Milkweed, Pleurisy Root
Botanical name Asclepias tuberosa
Plant type Herbaceous Perennial
Hardiness zone 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Growth rate Slow
Harvest time Fall
Height 1 ft. 0 in. - 2 ft. 0 in.
Width 1 ft. 0 in. - 2 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Clay
Flower color Gold/Yellow
Leaf color Green