There are close to 150 species of milkweed plants worldwide. About 25 of these are the only food source for monarch butterflies, and milkweed is an important nectar source for bees. And while a few species of milkweeds are edible to humans some are poisonous, and all should be treated with respect. If you don’t know what you’re doing, do yourself a favor and don’t do it.
There are about 20 edible milkweed species floating around, which is good! That being said, basically all of the different milkweed species contain alkaloids, cardiac glycosides, and toxic resinoids. As the scary names imply, these can all be bad. The secret lies in knowing what you’re doing when it comes to eating these plants, and don’t eat them at all if you can’t remember what the rules are. (Note: Make sure you refer to a reputable botanic key to identify plants, or have an expert show you.)
Common milkweed (Asclepias syriaca) is the most widely known and distributed edible milkweed, though it is definitely not the only one. Common milkweed looks very much like showy milkweed (Asclepias speciosa, see above), though the flowers of common milkweed are, of course, not as showy as the flowers above. Both are edible and can be treated the same way.
Here are some other edible milkweeds that are not as commonly known, including their reported edible parts. For these plants it’s important to consult a reputable edible plant resource that speaks to these plants specifically before consuming them (note: my source for the following is Plants for a Future, which provides wonderful information on edible and medicinal plants):
- Swamp milkweed (Asclepias incarnata, see photo below): flowers, leaves, oil, seedpod
- Purple silkweed (A. lanceolata): flowers, leaves, and seedpod
- Green milkweed (A. viridiflora): flowers, leaves, oil, root, seed, seedpod
- Butterfly milkweed (A. tuberosa, note all references say to either avoid this plant or consume in low quantities): flowers, leaves, oil, root, seedpod
- Purple silkweed (A. hallii): flowers, leaves, oil, seed, seedpod
The edible parts of some milkweed plants include the new shoots, which taste like asparagus and can be harvested in spring when they are less then 8 inches tall. The flowers and flower heads taste like peas, and can also be harvested. As the plant matures the seed pods can be picked when they are about 1 inch long or less; as the pods increase in size, they also increase in bitterness and alkalinity.
The root of milkweed may nor may not be edible, depending upon the source you’re consulting. My policy is that when it comes to conflicting information regarding whether a plant or plant part is edible, I err on the side of caution and don’t eat it.
Some sources say that young seed pods and shoots of milkweeds can be eaten raw, but I don’t recommend this. These sources also recommend only eating the raw plant parts in low quantities, and in my mind it’s always better to process plants that contain any alkaloids and toxins properly just to be safe. Processing the plant parts also removes bitterness, and just makes them taste better.
To process your shoots, flowers, and seed pods, place them in a pot, and cover them with boiling water (do not use cold water…make sure you boil it on its own first), then bring everything back to a boil. The water must then be discarded, and the process repeated two to three times. A tea kettle kept at a boil on the stove comes in handy for this.
To eat the plant parts after processing, boil them normally for about 15 minutes, until tender. You can serve them with butter, a sauce, or any other way you’d eat asparagus, peas and the like. Also feel free to include them in soups, casseroles, eggs, and more. They are very tasty. The flower heads can be boiled down to make a sugary syrup because of the sweet nectar, and feel free to pickle the seedpods in the same fashion as you make cucumber pickles.