How To Grow Butterfly Weed (Asclepias tuberosa) If you would like to attract a continuous visitation from various butterflies and hummingbirds to your garden (who wouldn’t?), consider adding Start Butterfly Weed seeds if you would like to attract beneficial insects to your garden! This milkweed flower seed is perfect for the butterfly garden. Several species of milkweed, or asclepias, are native to North America, and this year the Perennial Plant Association has chosen one of them as Perennial Plant of the Year: Asclepias tuberosa.
How To Grow Butterfly Weed (Asclepias tuberosa)
If you would like to attract a continuous visitation from various butterflies and hummingbirds to your garden (who wouldn’t?), consider adding butterfly weed to your flower garden beds this season. The one and a half to two and a half foot-tall perennial thrives in dry, sunny sites all across USDA hardiness zones three through nine. When mature, the butterfly weed boasts two to five inch clusters of yellow-orange to bright orange flowers.
The butterfly weed gets its name from providing the main food source for butterflies, specifically monarch’s, who use the butterfly weed as a host plant during their caterpillar and butterfly stages. The monarch, however, is not the only pollinator that is attracted to butterfly weed. Butterflies of all kinds, as well as honey bees, bumble bees, and hummingbirds, are all frequent visitors of the butterfly weed. Butterfly weed also attracts swallowtails, painted ladies, hairstreaks, and fritillaries. Unfortunately, patience is needed to enjoy what the butterfly weed can bring to your garden, as plants typically don’t flower until their third year. The wait may be long, but butterfly weed blooms do not disappoint. With a splendid array of bright orange flowers and a long list of frequent visitors, it is a good idea to have your camera ready.
An herbaceous member of the dogbane family, butterfly weed is native to the dry fields, prairies, meadows, woodlands, canyons, and hillsides of the eastern United States and Canada. It grows naturally in loamy or sandy well-drained soils in full sun locations. Butterfly weed is cultivated for its ornamental value and its flowers are used for the preparation of various cut flower bouquets.
Each butterfly weed plant develops an erect, multi-branched stem that grows around one to three feet high. Each branch is covered in hairs and becomes woody after a few years, developing flower clusters at the ends of each branch once the plant reaches maturity. Alternately arranged on the stem, butterfly weed leaves are lanceolate, linear, or oblong, with smooth edges and pointed tips. The upper side of the leaves are both darker and shinier than the under side.
Three years after planting, butterfly weed begins to produce bright orange flower clusters of small, five-petaled, star-shaped flowers. Blooming from May to September, butterfly weed packs a pollinator party throughout the growing season.
The fruit of the butterfly weed plant is a narrow greyish-green pod covered with hairs, which ripens at the end of summer or the beginning of fall. Each pod contains hundreds of seeds. The seeds are equipped with silky, white tufts of hair which help the seeds take flight on the wind to disperse and find new homes.
People and Pets Shouldn’t Eat It
All parts of the butterfly weed are toxic to both humans and animals. The flowers, stems, leaves, and root will all cause diarrhea and vomiting if ingested. Touching the sap could cause skin irritation. Eating just a small amount of butterfly weed can get you sick. This is even more of a danger with small animals, as tiny doses, as low as .01 to .05 percent of their body weight, could kill them. This is generally more of an issue with grazing animals than with pets, but exercise extreme caution with plant placement and seek immediate medical attention if you suspect that a child or pet has eaten butterfly weed.
Varieties of Butterfly Weed
True orange is the typical flower color of the original hardy, species version that is often sold as Asclepias tuberosa. “Hollow Yellow” is a yellow flowered variety. “Cinderella” is a cultivar with pinkish-red colored flowers. “Gay Butterflies Mix” is a family of species, with plants in colors of red, orange and yellow.
The “Silky Mix,” or Asclepias curassavica, has several beautiful variations of the original A. tuberosa. Silky Deep Red Butterfly Weed bears flowers with yellow-orange crowns and deep red-orange corellas for a lovely two-toned bloom. Silky Scarlet is a tropical species that is a perennial in frost-free regions and an annual in regions that experience freezing temperatures. The Silky Scarlet produces blooms that range in color from salmon and bright pink, to shades of yellow, orange, and red. Silky Gold produces golden yellow flowers that bloom all year long in frost-free areas.
Growing Conditions for Butterfly Weed
Butterfly weed performs best in full sun locations but can adapt to some shade, as long as it receives at least six hours of direct sunlight per day. Butterfly weed is adapted to less-than-ideal soil conditions, and is well-suited to clay, dry, and even rocky soil and drought conditions. Hardy to USDA zones three through nine.
Care of Butterfly Weed
Keep butterfly weed well watered during its first season but don’t worry about watering it once it is established. No fertilization is needed for butterfly weed. Just a topdressing of compost or composted manure added once per year is all that is needed to provide nutrients for butterfly weed to thrive.
How to Plant Butterfly Weed
Sow butterfly weed seeds directly into the soil in the fall for spring sprouts, or sow indoors during the winter after cold stratification. Because of their long taproots, direct sowing is the preferred method of propagation.
How To Propagate Butterfly Weed
Butterfly weed can be propagated by seed or by root cuttings. Because butterfly weed has a long taproot, which can be very difficult to transplant, propagation by seed is highly recommended. Seeds can be harvested and saved around the beginning of fall. They can be brought indoors or can be buried in the ground just under the topsoil, to survive the winter, then planted directly into your garden beds in the early spring.
Companion Planting With Butterfly Weed
The following plants will all grow well with butterfly weed:
- Russian Sage
- Ornamental Grasses such as fountain grass, northern sea oats, or switchgrass
Garden Pests and Diseases of Butterfly Weed
If you grow your butterfly weed in a very wet location, crown and root rot can be an issue. Reduce the risk of crown rot by planting your butterfly weed in a hole with the crown set just slightly above the soil line. Reduce the risk of root rot by increasing soil drainage and by taking care not to overwater your butterfly weed plants.
Yellow-orange oleander aphids (Aphis nerii), or milkweed aphids, form colonies which envelop the plant’s stems and leaves as the pests feed on the sap. The pests excrete honeydew in massive amounts, a clear, gooey waste substance that attracts a black, sooty mold. The mold covers the plant in layers of powdery, soot-like fungal strands. Small infestations of oleander aphids can be treated by knocking them off with a burst of water from the watering hose. Heavier infestations may need multiple treatments of insecticidal soap or horticultural oils, sprayed to saturate stems and leaves.
Common Questions and Answers About Butterfly Weed
Do you fertilize butterfly weed?
Feed with compost in the fall, then top with a layer of mulch. In spring, feed with a diluted dose of slow release fertilizer blend.
Does butterfly weed come back every year?
Yes, in zones where butterfly weed dies back in winter, it sprouts again in spring as a perennial.
Do you cut back butterfly weed in the fall?
Start with clean, sterilized gardening shears, and disinfect the tool when moving between plants. Wear gloves to protect yourself from the skin irritation butterfly weed can cause. Prune your butterfly weed between late winter and early spring before new growth sprouts. Cut the plant back to a third or half of its starting height. Make all your cuts no more than a quarter inch from a leaf or leaf node.
How do you propagate butterfly weed?
You can propagate butterfly weed from seed, via cuttings rooted in water, or by division or separation.
How often should I water butterfly weed?
Water young plants whenever the soil dries out to keep it moist until they’re well established and showing new growth. Once well established, butterfly weed should only need water during periods of extreme drought.
How tall does butterfly weed grow?
Butterfly weed grows to between one and a half and three feet tall when mature.
Is butterfly weed a perennial?
Butterfly weed is a perennial, which means they go dormant each winter and bounce back in the spring.
Is butterfly weed invasive?
Unlike common milkweed (Asclepias syriaca), butterfly weed (Asclepias tuberosa) does not have the quickly spreading roots that qualify it as invasive.
Is butterfly weed poisonous to humans, dogs, or cats?
Butterfly weed is toxic to both humans and pets. In humans, it requires large doses to cause discomfort, but because children, dogs, and cats are smaller, their risk is more substantial. Consumption of butterfly weed can cause bloating, fever, difficulty breathing, dilated pupils, muscle spasms, or death. For ingestion by humans, call the Poison Control Center at 800-222-1222, or for ingestion by animals, call ASPCA’s Animal Poison Control Hotline at 888-426-4435.
Want to learn more about growing Butterfly Weed?
Cornell University covers Butterfly Weed
Gardening with Charlie Nardozzi covers How to Grow Butterfly Weed
SFGate Homeguides covers Butterfly Weed Plant
Monarch Watch covers Milkweed
Plant Care Today covers Butterfly Weed Care
University of Wisconsin-Madison covers Butterflyweed
Andrea Bloser says
I just bought eight baby asclepiousa
tuberosa. How much space does each plant need?
Butterfly Weed Seeds – Asclepsias Tuberosa Milkweed Flower Seed
Butterfly Milkweed (Asclepias Tuberosa) – Butterfly Weed flower seed creates a beautiful butterfly-attracting plant. It has bright orange flower clusters that are flat and easy for butterflies to land on and drink the rich nectar. Being a member of the milkweed family, Butterfly Weed, will attract the monarch butterfly as well as other butterfly varieties.
The root of Butterfly Weed is the most commonly used part of the plant. It is broken down and powdered, used to treat pleurisy, a lung complication that causes trouble and pain with breathing.
Milkweed seed | butterfly
How to grow
How To Grow Butterfly Milkweed From Seed: Many gardeners recommend a cold treatment to help Asclepias Tuberosa seeds germinate more quickly. To do this, dampen a paper towel, place the flower seeds on the towel and seal it in a ziploc bag. Place the bag in the refrigerator for 3 – 4 weeks. After the cold treatment, start the Butterfly Weed seeds indoors. Do not cover the flower seeds as they need light to germinate.
Transplant the Butterfly Weed plants outdoors once temperatures are warm and plants have 4 – 5 leaves. Butterfly Weed care would include following a regular watering schedule during the first growing season to establish a deep, extensive root system. For a neat appearance, remove old foliage before new leaves emerge. Divide clumps every 2 – 3 years in early spring.
- Sowing Rate: 2 – 4 seeds per plant
- Average Germ Time: 28 – 42 days
- Keep moist until germination
- Attracts bees, butterflies and hummingbirds
- Depth: Do not cover
Asclepias Tuberosa plants are hardy and drought resistant. The blooms are followed by seed pods 4 – 5 inches long containing the seeds with their long silky hairs. The plant will die back to the root crown each winter, and it is slow to emerge in the spring. The foliage is lovely, too, extending its beauty beyond bloom time.
MSU Extension Floriculture & Greenhouse Crop Production
Several species of milkweed, or asclepias, are native to North America, and this year the Perennial Plant Association has chosen one of them as Perennial Plant of the Year: Asclepias tuberosa. This species, commonly known as butterfly weed or butterfly milkweed, has vivid orange flowers with nectar and pollen that are attractive to many species of butterflies and bees. The foliage of butterfly weed is not a preferred food but can support monarch caterpillars. This drought-tolerant plant grows best in a dry and sunny location, and is hardy in Zones 3 to 9.
Butterfly weed has upright stems with clusters of bright orange flowers that contrast nicely with the shiny green leaves. The stem sap is not milky, unlike others in the genus. This species of milkweed does not spread by runners like common milkweed (Asclepias syriaca) does, so it is not invasive. Butterfly weed is not attractive to deer; however, aphids can be a problem in garden settings and in the greenhouse,
Demand for this plant is likely to be high in this and coming years. Butterfly weed will flower readily the first year after seed sowing, but there are a couple of key points for success in producing it commercially.
Figure 1. Flowering of butterfly weed in response to day lengths from 10 to 24 hours. All plants received a nine-hour day and day-extension lighting was provided by incandescent lamps.
This species has some of the most dramatic responses to photoperiod we’ve seen. It is an obligate long-day plant, meaning that it requires long days for flowering. Plants grow rapidly under photoperiods of 14 hours or longer, and will begin flowering about eight to nine weeks after transplant when grown at an average of 68° F. However, if exposed to photoperiods of 12 hours or shorter, plants go dormant within a few days (Figure 1). Leaves become droopy, shoot growth apparently ceases, and existing flower buds may abort (Figure 2). Unfortunately, simply moving the plants back to long days will not restore them to active growth. To break this dormancy, a cold treatment of nine weeks or longer is needed; in our trials, all dormant plants exposed to 41° F for 15 weeks subsequently flowered.
To keep plants actively growing, it is absolutely essential to provide long days to these plants. We recommend providing a day length of at least 16 hours, or four hours of night interruption lighting. Photoperiodic lighting should deliver a minimum intensity of 2 μmol·m–2·s–1. Use lamps that provide both red and far-red radiation, like incandescent lights or LED bulbs designed to control flowering. Keep plants under these long photoperiods until natural daylengths are at least 14 hours long.
Figure 2. Flower buds aborting shortly after plant was moved to a nine-hour photoperiod.
Butterfly weed develops a large tap root, which can make transplanting or division of established plants difficult. In container production, it’s very important to use a well-drained medium, so consider adding extra perlite to a typical peat+perlite mix. Be careful not to over-water during production or during cold treatments. The taproot is attractive to fungus gnat larvae, so be vigilant and check the roots if plants lack vigor.
In outdoor settings, butterfly weed can reach 3 feet in height, but in container production, our plants were 12 to 18 inches tall at first flowering. Several plant growth retardants are reportedly effective for height control including sprays of daminozide (e.g., B-Nine, Dazide) paclobutrazol (e.g., Piccolo, Bonzi) and uniconazole (e.g., Sumagic, Concise). Using several plugs per pot, or pinching seedlings soon after transplant, can help to fill out containers.