Before covering butterfly weed, Asclepias tuberosa, I pass on the best butterfly weed tip I know: it emerges late in spring. It is by far the number one perennial I edit from the garden by accident in early spring before it has a chance to emerge.
Almost impossible for enthusiastic gardeners is to simply leave the perennial bed undisturbed until the butterfly weed has emerged. Marking the spot where Asclepias tuberosa resides with twigs (my mother’s choice during her gardening years) or stakes can make the difference.
You may find various showy cultivars of butterfly weed at garden centers but many are not reliably hardy. As with American columbine, the species version of Asclepias is the most reliable and in my opinion the most beautiful.
Butterfly weed does not like to be transplanted. With a species name like ‘tuberosa’, it makes sense that the fairly deep taproot does not like to be disturbed once the plant is established.
Butterfly weed, also known as milkweed, is native and extremely valuable in the landscape.
Asclepia tuberosa’s small flowers are prodigious producers of nectar, and bees and hummingbirds are enthusiastic patrons. In addition, milkweed provides food for butterfly larvae, notably the monarch butterfly.
One of the problems milkweed is facing in the environment is due to eradication by Roundup in corn fields. Genetically modified corn is immune to Roundup, allowing farmers to spray their cornfields with complete pesticide coverage. The corn lives and the butterfly weed dies, making it difficult for monarch butterfly larvae to find food. Learn more about the effects of genetically modified crops.
In addition to the threat from genetically modified crops, it is under pressure in the northeastern United States.
The orange color of the species is rare in the landscape, and the flowers have a somewhat waxy appearance. Leaves are typically blemish-free through the entire growing season and butterfly weed will slowly add size and flowers as the years pass.
Growing butterfly weed
Butterfly weed is recommended by others for full sun, and this is where it is happiest. I have seen milkweed shine in fairly shady spaces, including one spot behind and underneath the canopy of bottlebrush buckeye.
Hardy over a wide swath of the United States (zones 3-9), milkweed is tolerant of poor soil conditions. It can grow in places with high erosion, and it is a great plant to tuck in difficult places in the garden. You will often see butterfly weed growing along roadsides and in meadows. It is a prairie plant at heart I think, as it seems to grow best where conditions are toughest. Dry, hot, humid are not a threat to butterfly weed. Only our pesticides seem to be stopping it in its tracks.
The seed pods are extremely beautiful and if left on the plant, butterfly weed may self-seed around your property. It is not aggressive.
Asclepias tuberosa is extremely drought tolerant. In addition, butterfly weed has a reputation for being unpalatable to deer. Deer desperate for food will eat almost anything, but it is nice to know milkweed is not their first choice.
Dig a hole and plant it and then don’t disturb it. Over time your patience will be rewarded.
Scientific name: Asclepias tuberosa
Plant type: herbaceous perennial
Native status: native to much of North America. Native to the United States except for Nevada and the Pacific Northwest.
Winter hardiness: 3-9
Of note: Native perennial that is key to monarch butterflies. Small flowers produce a lot of nectar for butterflies and hummingbirds. Monarch butterfly larvae feed on Asclepias. Emerges late in spring…do not disturb area where planted. Does not transplant easily…has a long tuberous root – Asclepias tuberosa.