Asclepias Tuberosa (Butterfly Weed): Complete Guide On How To Plant & Care

Overview

Asclepias Tuberosa also referred to as butterfly weed or Indian paintbrush, Orange Milkweed is a species of milkweed native to eastern and southwestern America. It is commonly referred to as butterfly weed because of the butterflies that are attracted to the plant by its color and it’s copious of nectar.

At maturity, Asclepias tuberosa reaches heights of between 1 to 4 feet, displaying fuzzy stems and produces green sword-shaped foliage through spring and summer and clusters of small red, orange or yellow flowers. The plant dies back each winter, but it returns from its perennial root system each year if it’s kept properly pruned.

Plant Profile

Botanical NameAsclepias Tuberosa
Higher ClassificationMilkweed
Common NameButterfly Weed, Butterfly Plant, Pleurisy Root
FamilyApocynaceae
Type Of PlantHerbaceous Perennial
Soil PreferenceMoist, well-drained soil
Native RangeEastern And Southern United States
Bloom TimeJune to August
Light RequirementFull Sun (6 hours direct light)
FoliageDeciduous (seasonally loses leaves)
Landscape UsesContainer, foundation, massing, mixed border, patio/sidewalk
Hardiness ZonesZone 2, Zone 4, Zone 5 (Chicago), Zone 6, Zone 7, Zone 8, Zone 9
TolerancesDry sites, Alkaline soil
Season of InterestMid-summer, Later summer
Flower color & FragranceOrange & white
Growth RatesSlow
Diseases, Pests And ProblemsCrown Rot, Japanese Beetles, Monarch butterfly caterpillars, powdery mildew, Aphids

How Does Asclepias Tuberosa Look Like?

Asclepias tuberosa is a coarse perennial plant consisting of many stems. The stems are straight and very hairy. The leaves are alternate and simple. Unlike other species of milkweed, tuberosa does not contain the characteristic thick milky sap but instead has a watery translucent sap. The inflorescence is slightly rounded to flat and made up many individual flowers. The flowers are made up of five petals pointing down and topped by a crown of five erected hoods. The fruit is a pod containing numerous brown seed each with a tuft of silky white hairs.

Also Read: How to grow and care for Philodendron Martianum

How To Plant Asclepias Tuberosa

Where To Plant

Given that Asclepias tuberosa self-seed readily, you need to plant it at the back of the border or in a corner or in any other location where it will be easy to control its rampant spread. Generally, an area that shielded from free flow of wind is ideal as it prevents the spread of seeds.

When To Plant

When you are propagating Asclepias tuberosa from seeds, you will need to sow the seeds in your garden in the fall, which give them the period of stratification (exposure to cold, moist condition) they require to effective germinate in the spring. This will eventually ensure that your plant blooms in the following summer.

How To Plant

You can successfully plant Asclepias tuberosa in your garden from seeds or seedlings, though it is easily to propagate the plant by seed. When planting through seeds sow the seeds and ensure to keep the garden bed moist until the seedlings become established.  Though it is difficult to transplant once established, when planting from seedlings, plant with the top of the tap root about ½ to 1 inch below soil level. Ensure to plant about 15 to 18 inches apart, usually in group of 3 for vigorous growth.

How To Care For Asclepias Tuberosa (Butterfly Weed)

Light Requirement

Asclepias tuberosa are sun loving plants. Light directly influences plant growth and flowering by inducing photosynthesis and feeding plants energy.  When growing asclepias tuberosa in your garden bed, choose a location that receives at least 6 hours of full sun.

Soil

Asclepias Tuberosa grows well in sandy loam soil that stays relatively dry and well-draining. However, just like other milkweed varieties, it is extremely tolerant and will grow well in average garden soil without the need for fertilizer.

Water Requirement

Asclepias tuberosa is native to sandy, rocky banks and meadows where it thrives in hot and dry conditions. This plant has a very deep tap-root system that extends several feet below ground making it drought tolerant. Generally asclepias tuberosa thrives in conditions that replicate its natural environment-dry areas with little moisture. Therefore, when grown in containers or garden bed, there is no need of frequent watering.

Temperature & Humidity

Asclepias tuberosa tolerates a wide range of temperature and humidity.

Fertilizer

Asclepias tuberosa virtually do not require any maintenance once it is established.  It does not necessarily require fertilizer during their period of growth as they have ability to tolerate poor soils, including dry and rocky soil.

Propagating Asclepias Tuberosa From Seeds

  1. Soak the asclepias tuberosa seeds in tap water overnight and then after the seeds have soaked, put them in a sealed plastic bag.
  2. Refrigerate the bag of seeds for at least two weeks.
  3. Get seed tray with drainage holes and fill it with a germinating mix. A simple germinating mix can be prepared by taking garden soil or sandy soil and amending it with manure, peat moss, perlite or vermiculite.
  4. Get your seeds and sow them into the seed tray germinating mix. Make sure to sprinkle water over the soil so that the seeds do not get dry.
  5. Take the seed tray to a shade or any place with bright, indirect light.
  6. After a period of between 7 and 14 days the seeds will have germinated. Keep checking, please note that it is difficult to transplant asclepias tuberosa once it is established, therefore, once the seedlings have one or more sets of true leaves, transplant them into a 6-inch or 8-inch planters filled with a well-draining growing mix.

How To Cut Back/Prune Asclepias Tuberosa

Butterfly milkweed dies back each winter, but it returns from its perennial root system each year if it is properly pruned. Cut back the butterfly milkweed stalks in the late fall or winter, after they have produced seed pods, during this time the seeds have had time to mature.

  • Ensure that your pruning shears are dry clean and then wear gardening gloves to protect your hands from the sap which can cause skin irritation or inflammation.
  • Cut back the entire plant by one-third to one-half its previous height in late winter or early spring before new growth emerges. Make the cuts within ¼-inch of a leaf or leaf-bud so that the bush doesn’t have bear stems poking out.
  • Remove all pruning clippings from the bed after pruning and dispose of them.
  • Butterfly milkweed plant is known to spread and therefore if you do not have more room for butterfly milkweed plant, cut the pods off in the fall when the pods are tan and the seeds are coffee brown or wait until spring to cut back the entire plant.

Also Read: Different Types of Anthurium Varieties

Is Asclepias Tuberosa Poisonous?

All milkweed species contain cardic glycosides that are poisonous to both humans and animals they pose the most danger to grazing animals. However, severity or symptoms of milkweed poisoning depends on its age and how much has been ingested. Common symptoms of milkweed poisoning  in both humans and animals include:

  • Drooling
  • Nausea
  • Vomiting
  • Dilated pupils
  • Weakness
  • Seizures
  • Tremors
  • Abnormal heart rate

How To Deadhead Asclepias Tuberosa

Deadheading Butterfly milkweed is a great way to prolong blooms in early and mid-summer. After the first flush of flowers, simply cut off the flower above the topmost leaves on the stem. Removing the dead or wilting flowers prevents seed formation which encourages butterfly weed to produce more a second flush of flowers.

Which Plants Will Grow Well With Butterfly Weed?

Plant butterfly weed in the dry perennial garden with:

  • Coreopsis
  • Shasta Daisies
  • Russian sage
  • Coneflower
  • Catmint
  • Achillea
  • Gaillardia
  • Echinacea
  • Salvia
  • Rudbeckia
  • Ornamental Grasses such as fountain grass, north sea oats or switchgrass

Common Problems: Pest& Disease

Crown Rot

Crown rot generally affects all varieties of milkweed. It causes deterioration and rotting of the tissues at the crown of the plant causing the leaves to turn yellow, collapse and die. The disease is commonly caused by a fungus that develops in the soil when the garden has experienced many flash floods or heavy rain.

Japanese Beetles

Japanese beetles are destructive plant pests in both their immature and mature forms. The Adult beetles can gather in large numbers on your Asclepias tuberosa plant eating the leaves and petals until they take on a skeletal appearance.

 Monarch Butterfly Caterpillars

Monarch caterpillar eats leaves of all varieties of milkweed as food. This type of caterpillars has a potential of killing your entire butterfly weed.

Powdery mildew

Powdery mildew is a fungal disease that can affect butterfly weed and is prevalent during warm dry weather. The first sign of powdery mildew is pale yellow leaf spot, and then eventually white powdery spots can form on both upper and lower leaf surfaces and quickly expand into large blotches.

Aphids

Aphids are tiny pear-shaped, soft-bodied insects that suck the juices out of leaves and stems of plants. On butterfly weed, aphids tend to cluster at the growth ends and attach themselves to soft, green stems. If the infestation is bad enough, your butterfly weed will begin to drop leaves.

Also Read: Different Types of Alocasia

Frequently Asked Questions (FAQ)

Does Milk Weed Flower The First Year?

Generally, milkweed may not bloom in the first year of growth, because most of its energy is being used in growing a strong root system. Even in the second year, it may not bloom if the plant is stressed such as by drought or excess heat.

Why Is My Butterfly Milkweed Not Flowering?

The main reason why your butterfly milkweed is not blooming may be as simple too much fertilizer in the growing environment or lack of adequate sunlight. Butterfly milkweed grown along regularly fertilized lawns, gardens or crop fields are probably getting too much nitrogen, which can cause lush green foliage  growth with lack of blooms.

What Is The Best Time To Plant Milkweed Seeds?

Milkweed seeds should be planted in the fall. Exposure of seeds to cold temperatures and moist conditions during winter will stimulate germination.

Will Butterfly Milkweed Grow In Shade?

Just like other varieties of milkweed, butterfly milkweed love to grow where it is exposed to full sunlight. It grows effectively if planted in areas of your garden that receives at least 6 hours of full sunlight. It can grow under a shade; however, the growth will not be vigorous and in the end the plant will not produce blooms.

Does Asclepias Tuberosa spread?

Butterfly weed has does not spread by runners like other common milkweed species. It can only spread when seeds are dispersed by wind.

When Should I Cut Back My Milkweed?

It is recommended to prune the milkweed stalks to about 5 inches in height during the fall or early winter to discourage monarch caterpillars from establishing winter-breeding colonies.

How Do You Stop Common Milkweed From Spreading?

You can prevent milkweed from re-sprouting by spreading a 4 to 5 inch layer of mulch over the area where milkweed was removed. Common milkweed requires plenty of sun to grow and shading keeps it from growing. Growing a thick bush of flowering plants or shrubs also help to shade out milkweed from re-growing.

How Long Does It Take For Butterfly Weed Seeds To Sprout?

Cold-stratified butterfly weed seeds should germinate and sprout within 10-15 days.