Last Updated on September 16, 2022 by Plant Mom Care
Asclepias tuberosa or butterfly weed belongs to the Dogbane family and is a milkweed species of plants indigenous to South Canada and the United States. It is commonly called butterfly weed because the color of the flowers and its abundant production of nectar attracts butterflies including other types of butterflies, honey bees, native bees, butterfly moths, and hummingbirds.
The plant is a good food source for the larvae of butterflies, specifically the monarch and queen butterflies, including several species of moths.
This plant is a perennial, growing to 2-4 feet high, and spreads about the same distance. Its clusters of yellow, orange or red flowers bloom from summer to autumn. Some wild varieties have reddish-orange flowers.
The green seed pods turn brown when the seeds are ready and break open by themselves. The seeds are attached to little puffs of cotton, enabling them to fly with the wind and seeding themselves anywhere. Usually, the plant appears in late spring, hitting its peak flowering time from July to early fall, and dries on the stem in autumn and winter.
Besides enjoying the floral display of this plant, the stems can be used in cut flower arrangements. The seed pods are also very decorative and add a unique feature to flower arrangements.
Another benefit of cultivating this plant is that when it becomes established, it is drought-tolerant, with just a few pest problems, and can adapt to any soil type.
Butterfly Weed Light Requirements
Choose a location indoors or in your garden that gets several hours of bright sunshine, as this plant loves the sun. Full sun is definitely preferred, but this hardy plant can also tolerate some shade too.
Butterfly Weed Watering
You must maintain moist soil conditions for this plant during its first year of growth or until mature foliage growth appears. Once it appears to be established, water it just once a week or so, as mature plants thrive in dry soil since it tolerates drought.
Butterfly Weed Humidity
Because this plant can grow in hardiness zones 3-9, it thrives in a variety of humidity settings.
Butterfly Weed Temperature
These plants can tolerate temperature lows of 20-30°F with a maximum of 90°F. The temperature for ideal growth is between 70-75°F.
Butterfly Weed Soil
This plant can thrive in any type of soil, from clay to gravel, and prefers a neutral or slightly acidic pH. You probably have plants that are more demanding than this one, so let them dictate the soil type. This plant isn’t picky just as long as the soil is well-draining.
Butterfly Weed Repotting
This isn’t an easy plant to repot since the roots are deep and large. So ideally, it’s better if you grow it from seed in a 3-gallon pot or larger. Only repot it if it gets root-bound. Pruning down the plant will keep the plant manageable.
Butterfly Weed Propagation
The only way to propagate this plant is from seed. Remove the seed pods when they start turning brown before they burst open and plant them in fall to start growing in spring.
If you’re living in warm climates, the seeds might need cold stratification to prepare them for germination.
Fill a plastic bag with moistened sand and spread the seeds on top and store them in a refrigerator under a constant temperature of 70-75°F until the seeds begin to sprout. Carefully move them into moistened peat pots filled with good quality potting soil that is easily planted directly in the garden or pot.
Keep them watered and under bright artificial lighting or someplace with good sunlight and good airflow – running a fan on them twice daily for 15 minutes will ensure nice airflow.
Harden the plants for a week or so before transplanting by taking them outdoors in the day, bringing them back inside at night. Plant the pots directly into the soil or a large pot in spring as the peat will slowly break down.
Choose a place that gets good sun, ensuring the soil is well-draining, and plant them 1-2 feet apart. Water the seedlings twice weekly until they get established, then cut back since this plant prefers dry conditions.
Additional Care
This plant is low-maintenance and doesn’t require any fertilization—in fact, feeding it causes more damage than benefit, so just let it grow by itself. However, you can add a layer of every year in spring just as it resumes growing.
While it doesn’t need pruning, you can cut it back before winter when the leaves turn yellow and the stems dry out and turn brown. This indicates that the plant is going dormant. Deadhead dying flowers to keep it blooming longer.
You can leave a few flowers to form seed pods, but make sure to collect the pods before they open and the seeds can fly away in the wind and grow elsewhere. It isn’t invasive but can spread if unattended.
Butterfly Weed Common Problems
Aphids tend to feed on and damage this plant. Use sprays of neem oil or insecticidal soap against these pests.
Red milkweed beetles, both the adults and larva, love feeding on the foliage of this plant, including Monarch butterfly larvae. Control is not necessary unless the damage is too much.
Downy Mildew is a big threat to this plant and is caused by a fungus in water. Symptoms include gray-brown lesions that develop under the leaves into white, cottony fungal growth. Lower leaves might sometimes turn yellow or the taproot gets rotten.
This usually happens when the plant is overwatered or the soil stays water-logged. Stick to your recommended watering routine and ensure the soil/pot drains well.
Leaf spots cause necrotic areas to develop on leaves and are caused by several pathogenic agents. This usually happens in wet conditions and might become severe if many lesions appear or start to merge. Use a suitable fungicide to control the spread of the disease.
Rust causes powdery pustules of red-brown spores to appear on leaves and stems, causing stunted growth and discolored and yellow tissue. Use a suitable fungicide when you spot these symptoms.