Plant of the Month: Butterfly Milkweed

Presented by Jeffrey Fato
May 8, 2023

Botanical name: Asclepias tuberosa
Common name(s): Butterfly Weed, Butterfly Milkweed, Orange Milkweed, Pleurisy Root, Chigger Flower, Chigger Weed
Family: Apocynaceae

[MUSIC—EASY AND FUN]

[Jeffrey] Hello everyone. This month’s plant of the month is Asclepias tuberosa, also known as Butterfly Milkweed. This presentation will highlight the common names, distribution, characteristics, planting conditions, gardening tips, and uses and benefits. My name is Jeffrey Fato.

Asclepias tuberosa is from the family Asclepiadaceae, which is the milkweed family. You may have heard Asclepias tuberosa referred to by common names such as Butterfly Weed, Butterfly Milkweed, Orange Milkweed, Pleurisy Root, Chigger Flower, and Chigger Weed.

If we look at an etymological perspective on where Asclepias tuberosa‘s name came from, Asclepias is derived from Asklepios, the Greek god of medicine, and tuberosa refers to how the root of Butterfly Milkweed is full of knobs and bulges. The Native Americans used to chew the tough root of Butterfly Milkweed as a cure for pleurisy and other pulmonary ailments, which is why it was often referred to as Pleurisy Root. While some people may refer to this plant as Chigger Weed, this is mainly associated with the fact that Butterfly Weed can be found in habitats where chiggers can also be found.

Distribution

In terms of distribution, Butterfly Weed is distributed all throughout North America. As you can see in our two maps, in light green is where the species is not only native but very common, and in darker green on these two maps, this is where the species is native but less common. Butterfly Weed exists in its native habitat of prairies, open woods, canyons, and hillsides. It’s fine growing in rocky soils as well as clay and sandy soils. It’s very common in eastern Texas and becomes less common in Texas the further west you go.

Characteristics

Some characteristics of Butterfly Milkweed include that it grows into a beautiful bushy plant. It’s a herbaceous perennial often prized for its beautiful flowers, they’re very vibrant. It produces a large flat-top cluster of bright orange flowers and is native to Texas. The flower color can change depending on where in the United States it’s found, but generally in Texas, it takes on an orange pigment. Mature plants can get to about one to two feet tall and usually don’t grow wider than two feet. Their leaves are linear to oblong to lanceolate in shape and are alternately arranged. One key feature for identifying Butterfly Weed, in particular, is that the top leaf is generally darker green than the bottom part of the leaf. The corolla, hoods, and horns of the Butterfly Milkweed flowers are all orange and they are going to be glabrous, or lacking flower hairs. One of the tells, which you can see in the top right picture for the flower of Butterfly Milkweed, is that the corolla or the petals reflex backward. As I was saying before, Butterfly Milkweed flower pigment can range from orange to yellow blooms.

The fruit of the Butterfly Milkweed is a follicle, it’s going to produce a rather large seed pod that’s grayish-green but can vary. The pods are covered in short hairs and they will swell and burst when ripe. Whenever they do burst open, they release numerous round seeds covered in silky fibers that help with the wind distribution of these seeds.

Planting Conditions

While there are some recommended planting conditions for Butterfly Milkweed, it’s relatively hardy and can exist in a variety of soil types. It prefers well-drained soils but it can exist in sands and loams and different types of clays, but definitely clays that are more mixed with grittier material that encourage drainage. In terms of soil pH, it prefers slightly acidic to neutral soil. In terms of soil moisture level, it can be dry, it can be moist. Once again it’s going to prefer well-drained soils, but Butterfly Milkweed is going to have a high drought tolerance, making it perfect for planting in our area of Texas. Butterfly Milkweed prefers full sun but can exist in part shade, but expect it to take longer to mature and not produce as many flowers as one in full sun. This is a summer blooming plant. Typically, it’s going to bloom between May and September.

Gardening Tips

There are several gardening tips that I’d like to impart on you today. In terms of propagating, you can very easily propagate Butterfly Milkweed from seed, but you can also do root cuttings. If you’re interested in doing root cuttings, what you should do is, in the fall, you should collect taproots from an existing Butterfly Milkweed and then you want to cut those taproots into about two-inch sections and then plant them vertically. I would recommend doing this maybe in a greenhouse because you want to keep the moisture level rather high. What you’re trying to encourage is that taproot to then produce more roots itself. You can try using rooting hormone, but from what I researched, you don’t necessarily have to. This might be a fun project to try if anyone’s interested in propagating Butterfly Milkweed in this way.

If anyone has worked with milkweeds before, you know that they’re all going to eventually get aphids. You can remove aphids in a variety of manners: you can pluck them off the plant, you can brush them off with a brush or a broom, or you can spray them off with either high-pressure water or you can try using a soap-water mixture. But what I recommend instead is to try companion planting or to plant native plants alongside your Butterfly Milkweed that will attract pest insect predators that will eat the aphids. My recommendation is to try and encourage ladybugs to enter your garden, as ladybugs are one of several predators of the aphids. If you want to attract ladybugs while Butterfly Milkweed can attract ladybugs, you can also try planting Butterfly Milkweed alongside Tickseed or Coreopsis species or sunflowers because both of these species are going to attract ladybugs alongside the Butterfly Milkweed. As you can see in the top right, ladybugs will always go back and eat another aphid, so these will keep your plants clean and keep our native insects well fed.

Typically, Butterfly Milkweed seed pods are going to open in the late summer and early fall, and it’s recommended that you don’t clip the seed pods and instead wait until the seed pods open before doing collections, as you have a better chance of germinating more of the seeds if you wait till they’re all mature. One of the things to take note of is Butterfly Milkweed is a rampant self-seeder, so if you are interested in keeping your plant from self-seeding, you would clip those pods before they reach maturity. You may notice when you start to work with Butterfly Weed that it might contract a fungal disease such as rust or leaf spots, but this isn’t going to kill the milkweed; it’s more going to affect just how it looks cosmetically. What I can recommend is that if you see this happening on your plant and you would like to do something about it, remove all the sick leaves and throw them in the garbage because we don’t want to put them in the compost and then encourage that fungus to propagate and then further infect your plants in the future. After you’ve removed those sick leaves, you need to make a peroxide dilution and spray that on your plants as well as on the soil, and you do that by adding four parts water to one part hydrogen peroxide, and this should be enough to kill the fungal spores. I recommend from my past work using peroxide solutions to remove fungi that you do repeated applications in a small time frame, so you should check your plants periodically in case they do contract a fungus and you would like to get rid of it.

When planting from seed, I recommend that you scatter the seed fresh in the fall as they propagate rather well when fresh. You can try some forms of scarification, but there’s not much that scarification can do to increase germination rates; it germinates rather well on its own. One of the things that may happen, and this happens with several other milkweeds, is that the Butterfly Weed might enter dormancy in the winter, and you can see this in the mid to late fall if the leaves begin to get yellow and the stems begin to dry out and turn brown. If you notice this, you can just go ahead and cut the plant down to the ground. It will re-emerge in the spring. I’ve had several of my own milkweeds at my house that I’ve done this to, and they’ve gone down to the ground, and I thought they were completely gone, and they happened to just appear miraculously one day with several leaf nodes on them. So, have hope and just make sure you come back and check in the spring if you do happen to cut your milkweed down.

Lastly, depending on soil conditions, we went over what the milkweed prefers, but like we said, it is hardy. Your milkweed might not mature and establish itself as quickly if it’s not in its preferred conditions and therefore might not produce these beautiful vibrant flowers, which we’re used to seeing with Butterfly Milkweed, for about two to three years. That being said, once your Butterfly Milkweed is established, they can live for years, and their blooms will only get thicker and thicker.

Uses and Benefits

There are several important uses for why we need to start incorporating Butterfly Milkweed into our gardens. Obviously, from an aesthetic value, they are an ornamental plant; they are beautiful, showy, and long-living perennials that don’t take a lot of maintenance. They are also extremely important in terms of supporting pollinators. They can attract a variety of different butterflies and moths, bees and wasps, and hummingbirds, but there is a special value that’s attributed to Butterfly Milkweed in terms of supporting native bee populations, bumblebees, and honeybees. It’s important to take note that a lot of our different plants are larval hosts, and a lot of our milkweeds support a variety of butterflies, but Asclepias tuberosa in particular is going to be the larval host for Monarch butterflies, Queen butterflies, and Gray Hairstreak butterflies.

Like I was speaking on before, about how companion planting can attract natural pest predator insects, Butterfly Milkweed is a beautiful addition to support conservation biological control, i.e., this plant is going to not only attract pollinators, but it’s also going to attract a variety of pest insect predators. Like I said before, this plant can attract ladybugs, but it can also attract lacewings, damsel bugs, as well as minute pirate bugs, all of which are going to attack specific predators that may be plaguing your garden.

Also, Butterfly Milkweed is going to have a high resistance to deer; it actually repels them. And like we said before, this is a drought-tolerant plant, so it is great for planting in our area, and it’s native to most of Texas, so it is a plant that you should highly recommend to your fellow Texans.

Thank you, everyone, so much, and please go out and find yourself a Butterfly Milkweed.

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