How to Plant, Grow, and Care for Butterfly Flower

With a name like butterfly flower, it isn’t hard to imagine the role that this plant serves in the garden. A favorite among pollinator enthusiasts, this flowering perennial deserves a spot in any garden. It works especially well in pollinator gardens. 

What is Butterfly Flower?

You probably know this plant by its common name, which is milkweed. However, there are more than 70 species of milkweed native to North America. Each has different characteristics and comes from different regions. So, to group them all together would be to ignore the uniqueness of each species.

Butterfly flower, or butterfly weed, is a species of milkweed that is known for its extensive native range. But, perhaps it is more well known for its role in the lifecycle of one of our favorite pollinators, the Monarch butterfly. Milkweeds are the sole larval host plant of the Monarch. Without these plants, the population would become extinct quickly,

Planting this milkweed in your garden will draw butterflies in large numbers. It is not only a larval food but also an excellent nectar source. Let’s take a look at butterfly flower, or Asclepias tuberosa.

History

The first collected samples of milkweed plants were sent to Europe during the 1500s and 1600s by English explorers. The name Asclepias comes from the Greek word for medicine.

Some Native American tribes harvested parts of the plant for making cloth and ropes, and as a food source.

Parts of this plant are poisonous, though, so do not eat it!

Native Area

Butterfly flower is native to a large portion of North America, ranging from Maine to South Dakota and south to Florida. It is also native to Canada from Ontario east to the Atlantic coast. It is commonly found in open prairies and grasslands where it gets plenty of sun and air circulation. 

Characteristics

Butterfly flower is a small, perennial, shrubby plant that reaches between one and three feet tall at maturity. Upright, brown stems are flanked with lanceolate leaves, occasionally branching toward the top. For milkweed, this species has attractive and dense foliage, which creates a nice backdrop for the flowers. 

Colorful umbels of flowers in gold and orange sit atop the stems. Each cluster is about two to five inches across and made up of many small flowers. The flowers are tiny and star-shaped with a small yellow center. They are very nectar-rich so pollinators enjoy the abundance of nectar to be accessed in a small space. 

In fall, pollinated flowers give way to long, attractive, brown seed pods. The seed pods break open, revealing many small brown seeds attached to fluffy white silk-like fibers. These fibers help the seeds travel. Unlike most types of milkweed, this one does not contain a white milky sap within its stems and leaves. 

Uses

This plant is most often used as an ornamental, but I always say that you don’t plant milkweed because it looks nice. You plant it for the butterflies. Monarchs lay their eggs on this plant. When they hatch, the larvae will completely strip the plant of foliage in a matter of days. This leaves you with bare stems, which is not too pretty.

The flowers are showy, and the stems are strong, so this plant actually makes a nice one for the cutting garden. Otherwise, butterfly flower is mostly planted to attract and feed pollinators rather than for its ornamental beauty. 

There are other practical uses found for parts of the plant. The seed fluff is used to fill pillows and as a fire starter. Various textiles, ropes, and paper can also be made from the fibers of the plant. 

Where to Buy Butterfly Flower

You will find butterfly flower plants in most nurseries in summertime. These can be planted directly into the garden. They grow well from seed. If you prefer a different color, check out the sunny ‘Hello Yellow’ variety. 

Planting

Butterfly flower is a hardy perennial throughout the United States. The plant goes dormant in early winter, re-emerging in spring. Seeds can be planted in spring or fall. If you sow your seeds in fall, they will bloom earlier in spring. Planting in spring is perfectly fine, as these are mainly summer bloomers. 

Directly sow your butterfly flower seeds about ¼” deep, planting three seeds every one to two feet apart. Your seeds should sprout in about three weeks as long as the soil is warm enough. When they are three inches tall, thin your plants to one every one to two feet. 

How to Grow

Butterfly flower, like all milkweeds, is exceptionally easy to grow and maintain. Because they have such a wide native range, these plants are well-adapted to most climates. Once they are established, they are almost invincible. 

Light

Most milkweeds, this one included, perform best in full sun. In most climates, it would be difficult to give your milkweed too much sun. In warm climates with hot summers, give your plants some late afternoon shade. This will give them a break from the intense heat. 

Water

This plant is drought-resistant and shouldn’t be watered frequently. In most environments, this plant won’t need any supplemental water. The exception is in times of lasting drought. During a drought, you should water your milkweed deeply but infrequently. Allow the soil to dry in between waterings. 

Overwatering these plants is one of the most detrimental habits. If you water your butterfly flower too much or too often, it can develop a lethal fungus in the root system. This can kill the plant entirely. The plant’s long taproot contributes to its drought tolerance.

Soil

This perennial plant likes dry to average soil and doesn’t tolerate wet feet. Well-drained soil is imperative to avoid that dreaded root rot. The composition of the soil is not as important a factor as drainage. But in general, loamy, sandy, and gravelly soil types work well. This plant tolerates clay better than most. 

The long taproot that makes butterfly flower drought tolerant also makes it more difficult to transplant. Once you’ve selected a spot for this plant, it is best to leave it where it is. Moving to a new location is discouraged.

In terms of soil pH, these plants prefer soil that is slightly acidic to neutral and has a lower salt content. The immature plants are sensitive to salt and ammonium, but this decreases as the plant ages. 

Temperature and Humidity

Asclepias tuberosa is hardy in USDA Zones 3-9, so it tolerates a fair amount of cold weather. The portion of the plant above ground will die back after a freeze but will return in spring, as the roots are hardy. Likewise, these plants are highly heat tolerant and withstand temperatures as high as 113°F.

Humidity is not a main factor in growing butterfly flowers. With such a wide geographical range, it adapts to both high and low humidity with ease. Overall, this is a very tough plant that thrives in an extensive range of climates. 

Fertilizing

You should only need to fertilize this plant once a year, in spring. Of course, like most plants, this one will benefit from adding some compost or other organic fertilizer at the time of planting.

After that, a once-yearly application of a balanced fertilizer will do the job. Milkweeds prefer balanced nutrients, so use a 10-10-10 or 20-20-20 formula. Liquids are gentler than slow-release fertilizers, and natives like milkweed don’t need more than a side dressing of compost.

Maintenance

You may be tempted to cut back your plant after it has been stripped by caterpillars. There is no need to do this. This will only serve to reduce the amount of food for the next generation of Monarch larvae. If you’re able to wait out the bare stem phase, your milkweed leaves will grow back. This usually happens just in time for another round of caterpillars to move in. 

This flowering plant does self-seed vigorously. The best time to do your pruning is after it has gone to seed but before the pods open. When the pods first develop, they will be green and flexible.

Once they mature, they will dry on the outside and eventually split, releasing lots of small seeds. Before the seed pods ripen, in late September or October, cut your plant back to about six inches from the ground. 

Growing in Containers

Butterfly flower has an upright growth habit, which makes it good for growing in containers. Spring is the ideal time to plant these in containers. They should be placed in large pots because of their long tap root and fast growth. A 14”-16” container should work well for a single plant. 

Even though they can thrive in poor soil types in the ground, these plants should have more fertile soil when potted. Potted plants need to be watered more often than those in-ground, which aids in washing nutrients out of the soil. 

Rich soil will keep your milkweed plants growing robustly. Make sure that the container you choose has good drainage. Water your potted plants every other day as needed when the top inch of the soil is dry. 

While this plant is generally cold-hardy, in containers it is less so. Butterfly flowers should be pruned back in fall. Then the container should be brought indoors or otherwise protected. The roots of potted plants are more vulnerable to cold than those in the ground. 

Propagation

Planting seeds is an effective way to propagate this plant. All types of milkweed grow well from seeds, and the plants self-seed readily in fall. So much so that you may want to remove the pods before they ripen. This will prevent having too many of these plants popping up in spring. 

Direct sow seeds in fall or spring, or start your seeds indoors over the winter. Remember that these plants have long tap roots that don’t like to be disturbed, so transplant your seedlings while they are small.

You can also reliably propagate this plant by taking cuttings and rooting them in water. Cut your stem cuttings and dip the end in rooting hormone. Place your cuttings in a moist potting medium made up of potting soil, sand, vermiculite, or a combination. Keep your cuttings consistently moist, and they should root within two to three months.

Common Problems

Lack of Flowers

Butterfly flower needs full sun. When they are planted in partial to full shade, they may fail to bloom completely or very scarcely. These plants typically bloom their first year, so if your milkweed is not blooming, it probably needs more sunlight.

Pests

There are a handful of garden pests that may come after your milkweed, including caterpillars, if you count them as pests. However, these host monarch butterfly larvae, and leaving them be is best for the ecosystem. Milkweed bugs are a culprit in damaging these plants. They sometimes feed on the tissue and seeds of the plant and, occasionally, eat small caterpillars. Mostly they feed on aphids.

Oleander aphids are also known to feed on milkweed, but these are not usually a great issue. A great way to fend off pests is by attracting beneficial predatory insects. Ladybugs and lacewings are great for this purpose. However, none of these pests have a largely detrimental effect on milkweed, even in large numbers.

Because they are butterfly larval food, it is best to avoid using pesticides. Chemical pesticides will also harm the beneficial insects.

Diseases

Most disease issues will involve fungus in this type of plant. There are good plant hygiene practices that can drastically reduce the occurrence of these diseases. Watering the roots of the plant, and not the leaves, will help to keep them dry. Wet leaves are a breeding ground for fungus. 

Another important way to avoid fungal issues is to thin out your plants. This allows for better air circulation. If you do notice leaves affected by disease, remove the affected foliage as soon as you spot it. Spraying the plant with a solution of four parts water to one part hydrogen peroxide will kill the fungus spores. 

Cucumber mosaic virus can affect some Asclepias species, but it is often not a huge issue. You can remove infected plants and avoid planting in the area to prevent spreading this disease to other susceptible species.

Frequently Asked Questions