If you could save a species and help other pollinators by planting just one type of flower, would you do it? By planting milkweed this spring you could help save the monarch butterfly and other pollinators as well, such as native bees, honey bees, butterflies, moths, and hummingbirds.
The Monarch butterfly’s population has been cut by 90% in just two decades, mainly from widespread use of the herbicide Round-up (glyphosate), which kills milkweed–the only food source for the monarch caterpillar. I know that Monarchs used to be a common sight in my yard in late summer. But last summer I saw just two. You probably have noticed a decline as well. We need to right this wrong.
The monarch caterpillar eats only milkweed during its larval stage. And adult butterflies will only lay eggs on the plant. For other pollinators, milkweed is a good source of pollen and a great source of nectar.
The good news is that you can easily help the Monarchs and pollinators by growing milkweed in your yard.
How to Grow
Milkweed is easy to grow! Here’s how to do it.
To Grow From Seed
According to Toadshade Wildflower Farm, seeds are the best way to grow milkweed, since milkweed often has a tap-root. And tap roots don’t always like to be transplanted. Growing seeds gives you another advantage–you don’t have to worry about neonicotinoids or other systemic pesticides that could be on plants sold by nurseries. And seeds are cheap.
The seeds need cold to germinate. This is called cold stratification. This is easy to do by simply putting a packet of seeds in the refrigerator for at least 30 days. You do not need to take this step if you are sowing the seeds in the fall.
To start seeds outdoors (the best way because you are not transplanting), sow them 2 to 4 weeks before the average last frost or up to 8 weeks before first fall frost. Then be sure to keep the soil moist–unless there is rain.
To start seed indoors, plant them 6 to 8 weeks before the average last frost. Grow them in peat pots and transplant them while they are still small, as their roots are sensitive to transplanting.
Botanical Interests sells 4 different varieties of milkweed seeds.
To Grow From Plants
I have two words of advice if you choose to buy plants. One: Make sure they haven’t been raised with neonicotinoids or pesticides on the plants. Neonicotinoids can stick around for years and will eventually kill a pollinator. Two: Choose plants with small root growth, not larger plants. This is because a smaller tap-root will suffer less transplant shock once planted.
Prairie Moon Nursery offers bare root plants or plants in potted trays (a good way to get a lot of plants for a great value). They do not use neonicotinoids on their plants.
To Grow From Cuttings
It is possible to grow milkweed from cuttings. Simply make a cut from an existing plant underwater, then dip the cutting in hormone rooting powder. Plant it in sand or potting soil. Keep it moist while roots develop.
The Major Types of Milkweed
All varieties are perennials, summertime bloomers, and deer resistant. Once established they tend to be drought tolerant too. Pollinators seem to love them all. The four most common varieties are below.
Common Milkweed (Asclepias syriaca) Common milkweed used to be common, growing in nearly every nook of the United States. Unfortunately that is no longer the case. It will tolerate every soil condition, except for extreme wet. Native to much of the United States, except for the west. Has a sweet scent. 3′ high Zones 3-8.
Rose Milkweed (or Swamp Milkweed) (Asclepias incarnata) This variety has a more cultivated appearance than common milkweed and less likely to spread. Deeper pink flowers, also available in white. The leaves are narrower. A good choice for a flower bed. Will thrive in sunny spots, medium to wet soils. But will also tolerate drier conditions and part shade. Has a sweet vanilla scent. 4′ high. Zones 3-9.
Showy Milkweed (Asclepias speciosa) Grows best in well-drained soils, spreads by rhizomes. Plants have green to silvery-green foliage and stems that are often soft and fuzzy. In summer, the star-shaped pink to white flowers are followed by decorative, woolly seed pods. Native throughout the west and midwest of the U.S.
Butterfly Weed (Asclepias tuberosa) The Perennial Plant for 2017. This variety of milkweed is easily distinguished because of the vivid orange flowers and its shorter stature (usually 1-3′). Great for a sunny spot in a medium to dry area. Works in a variety of gardens. Zones 3-9.
Look for other ornamental varieties such as: Antelope-Horns Milkweed (Asclepias asperula), Purple Milkweed (Asclepias purpurascens), Prairie Milkweed (Asclepias sullivantii) California Milkweed (Asclepias Californica), White Milkweed (Asclepias variegata), Whorled Milkweed (Asclepias verticillata), Mexican Whorled Milkweed (Asclepias Fascicularis), Desert Milkweed (Asclepias erosa), and Green Milkweed (Asclepias viridis).
Want to learn which varieties of milkweed grow best in your area? Take a look at the helpful document by Monarch Joint Venture.
Where to Grow It
Despite having “weed” in the name, milkweed can look great in a variety of situations. Try Rose or Butterfly Weed in your flowers beds. All varieties work in a wildflower bed or more natural looking areas. I will be adding Rose Milkweed to my perennial bed this year. My neighbors have allowed a patch of Common Milkweed to flourish at the far edge of their lawn. The pollinators, including my bees, love it. Experiment with different varieties and have fun with it. Think too about your community, town, or city. Are there places where milkweed could be allowed to grow without spraying? Talk to your local officials. Talk to your neighbors.
So go ahead, give milkweed a try this year. Let’s save the Monarch butterfly.
This article was updated on March 19, 2018.