Common milkweed: how to eat your Monarch butterfly garden

Last Updated on May 17, 2022 by Aaron von Frank

In this article, you’ll find out how to grow and use common milkweed (Asclepias syriaca) — or identify it in the wild. Common milkweed isn’t just a beloved host plant for Monarch butterflies, it also has a variety of edible parts that can be eaten from spring through summer. 

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Milkweed edibility/safety warning:

Let’s get this part out of the way right from the beginning: some species of milkweed are edible (with caveats) while other species are poisonous. Due to hybridization where species’ growing ranges overlap (aka introgression), some “edible” species of milkweed have significant variation in flavor, thus rendering them virtually inedible due to strong bitter flavors.  

Don’t ever eat a plant you’re not 100% certain you’ve positively identified and know to be edible. Also, with any new food you’ve never eaten before, it’s always a good idea to only try a small amount your first time to make sure you don’t have any allergic reactions. 

Plants and humans are both highly complex chemical factories. If you’re taking certain medications or have underlying medical issues, chemical constituents contained in certain foods could be dangerous to you. Likewise, certain foods that are normally safe should be avoided during pregnancy or breastfeeding. When in doubt, consult your doctor or other qualified medical expert.   

With those warnings out of the way, let’s dive in…  

Knowing the virtues of your local milkweed 

We’ve previously written a detailed guide about how to raise Monarch butterfly caterpillars at home. Depending on where you live and how comfortable you are with plant identification, one of the biggest challenges in raising Monarchs is sourcing enough fresh, high quality milkweed to keep your caterpillars well-fed and healthy. 

In case you’ve never heard of it, milkweed is a genus of plants that emit a white latex sap similar in appearance to milk, hence their name. There are over 200 distinct species of milkweed around the world and many hybrids where species’ ranges overlap. We’d encourage you to do a google search to learn more about the milkweed species native to your area. 

For example, the milkweeds we see here in Greenville, SC, are almost always subspecies of Asclepias tuberosa, aka “butterfly weed.” Interestingly, despite their name, Asclepias tuberosas are actually not very popular with Monarch butterflies as a host plant (the flowers are quite popular as a food source for adult Monarchs and other insects). This is because A. tuberosa has very low cardenolide levels, the chemical compounds Monarchs utilize to make themselves unpalatable/poisonous to birds and other predators. 

On the flip side, butterfly weed’s low cardenolide levels make A. tuberosas one of the safest edible milkweeds for humans. Despite this virtue (from the human perspective), we don’t intentionally grow A. tuberosa in our garden because it’s not an ideal host plant for Monarchs. 

Of the multiple species of milkweeds we’ve intentionally grown, our favorite is common milkweed (Asclepias syriaca) for reasons we’ll detail below. 

Is common milkweed (Asclepias syriaca) edible? 

Common milkweed is edible to humans, with a few caveats. It’s also a very popular host plant for Monarch butterflies. 

The parts of the common milkweed plant that can be eaten by humans include: 

• tender young shoots as they emerge from the ground,
• young leaves,
• unopened flower buds,
• opened flowers (which change in flavor as they develop),
• young pods (the older pods are too tough/fibrous to be edible),
• immature seeds and silk inside the pods.  

Where is common milkweed (Asclepias syriaca) native? 

Common milkweed has a wide geographical range throughout North America. Wildflower.org lists it as a native plant in 39 states, from “Saskatchewan to New Brunswick; south to Georgia; west through Tennessee to Kansas and Iowa.” 

Even though common milkweed grows from Ag Zones 3-9 and is technically native to South Carolina, we’ve only very rarely seen it growing in the wild here — and only in the most northern, mountainous regions of the state. On a family trip to New York a couple years back, we were shocked by how abundantly common milkweed grew there, seemingly filling every open field and roadside. 

If you want to grow milkweed on your property as a host plant for Monarch butterflies and common milkweed is NOT native to your area, it’s better to find a species of milkweed that is native to where you live. Not only will it grow better, it will also be what Monarchs are accustomed to utilizing in your region. 

We grow common milkweed in our garden because:

• Monarchs favor it as a host plant;
• it produces a huge amount of vegetative growth relative to most other milkweed species/varieties, making it ideal for raising Monarchs;
• it’s an easy-to-grow perennial that’s native to our area;
• we (humans) can also utilize it as a food crop. 

Growing common milkweed in your garden 

We’ve been growing common milkweed in our gardens since 2018. The first thing you should know about growing common milkweed is that it’s a perennial plant that can aggressively spread via underground rhizomes/runners and take over beds within a few years. We’ve seen common milkweed runners pop up 6′ away from the parent plant. Plan accordingly when growing it in your garden.

We have one large common milkweed patch that’s growing in a dry-stacked stone bed which makes it virtually impossible to escape via runner. In another patch, it’s intermingled in a guild with raspberry canes and pawpaw trees, and we can easily remove any milkweed runners that come out of the bed in order to keep it contained. 

Another important growing note: it wasn’t until the third year of growing that our common milkweed patches seemed to really find their groove and take off, both in new shoot production as well as leaf and flower production. Until then, they seemed to be getting established in their new spot. We also didn’t harvest the shoots or leaves for the first two years so they could put all their energy into getting established.     

How to grow common milkweed: 

Common milkweed can be grown from seed or root cuttings. Obviously, you need to have access to plants in order to utilize root cuttings, so most people simply grow it from seed, as we did. 

Here’s how to grow common milkweed from seed: 

1. Get milkweed seeds.

Get your common milkweed seeds from a good source, such as Park Seed.

One study of common milkweed found that 66% of plants analyzed in the wild were the result of self-fertilization, so you don’t need a lot of genetic diversity of milkweed in your garden in order to get pollination and edible pods.  

2. Cold stratify your seeds. 

Milkweed seeds require cold stratification to germinate. Here’s how to cold stratify your milkweed seeds: 

• Option 1: In your fridge (quick method – 1 month): Wrap the seeds in a slightly damp paper towel, and place paper towel in a ziplock bag in your fridge. Set calendar reminder for one month, then remove seeds and germinate in biodegradable seed starting cells at room temperature. 
• Option 2: Outdoors (long method – over winter): Sow your seeds in containers (with potting soil and a thin 1/2″ layer of mulch) and leave them outdoors to overwinter. 
• *You can sow milkweed seeds directly in your garden in the fall to overwinter and germinate in the spring. This method will lead to lower success rates, especially in no-till, mulched garden beds like ours. You’ll also need to make sure: 1) you don’t mistake them for weeds and pull them, or 2) they don’t get crowded out by germinating weed seeds.  

Additional notes:

• Milkweed seed sowing depth should be 1/4″. 
• Plant two seeds per cell since germination rates can be in the 60% range.       

3. Maintain adequate soil moisture and light levels after germination.

If starting seeds indoors, keep the seed starting mix damp, but not wet.

Also, make sure seedlings have at least 6 hours of light per day. The easiest way to ensure adequate light indoors is with an indoor grow light system. 

5. Transplant seedlings after last frost date.

Don’t transplant your common milkweed seedlings until after your last frost date. Also, only transplant seedlings six weeks after germination and/or after plants have at least two sets of true leaves.

Select a full sun spot that gets a minimum of 6 hours of direct sunlight per day. Mature common milkweed plants grow to be 3-6′ tall x 2′ wide and begin forming dense patches within three years.  

How much common milkweed should you grow in your garden for Monarchs AND to eat as a vegetable? 

If you’re trying to figure out how much common milkweed to grow in your garden or how much square footage to dedicate to the plant, we’ve got bad news: the answer is “it depends”… 

How much space do you have available? How many family members will be dining on milkweed with you? 

For the sake of providing more habitat with healthy host plants for Monarchs, we’d recommend devoting as much garden space as possible to growing common milkweed.   

Thankfully, we have a large garden so we have about 100 square feet of dedicated common milkweed space. Our patches are still relatively young, so we harvest sparingly. Over time as our patches mature, we’ll be able to get larger yields for our personal consumption. Like other perennials, growing common milkweed for food requires patience; rewards come with time.    

How to identify common milkweed 

Trying to identify common milkweed in the wild? Here are key features of the species:

General: 

• usually growing in disturbed fields, roadsides, or other open areas; 
• milky sap drips out when leaves, stem, or flower stems are cut or removed from plant; 
• mature plant grows in colonies, not as a single plant;
• 3-6′ tall at maturity. 

Leaves & stems:

• leaves grow in a decussate arrangement, meaning each pair of leaves grows opposite each other on the stem and at a right angle to the leaf pairs above and below it on the stem.
• large pinnate leaves (resemble feathers) up to 10″ long with short, stout petioles where leaves and stem connect; 
• smooth leaf margin with white or pinkish central leaf vein (we’ve seen variation in leaf vein coloration within the same genetically identical colony); 
• leaf underside lightly colored compared to leaf tops with prominently raised veins; 
• rounded or slightly pointed leaf tips; 
• stems are hollow when cut; 
• stems are slightly fuzzy; 

• no branching – new leaves emerge from top of plant;
• raw young leaves taste mild and spinach-like with no bitter flavor. (*Don’t ID milkweed by taste first — if something you think is a common milkweed based on other factors turns out to taste bitter, spit it out since it’s likely an inedible or poisonous lookalike.) 

Flowers: 

• flower buds/inflorescence form at top of plant from their own stalk (aka peduncle) and each flower bud has its own small, slightly hairy stalk (pedicel) attached to a central point (umbel form); 
• mature plants can have more than one flower cluster; 
• dozens of individual flowers form on each round inflorescence; each flower has a central crown with five hoods which project out from the petals.   

• unopened buds are green with red sepals, but buds ripen to purple just before opening;
• when open, individual flowers tend to be pink/purple in color with white accents; 
• flowers are highly fragrant, nectar-rich, and sweet flavored (flavor develops and changes with time);
• flowers droop then desiccate after maturing, leaving behind small pollinated green pods (not true botanical pods, despite visual similarities) which hang down from pedicel;
• Common milkweed pods look similar to pods from other milkweed species, so pods are not a good method of identification. 

Common milkweed lookalikes: 

There are other milkweed species that look very similar to common milkweed. For instance, we grow showy milkweed (Asclepias speciosa) and spider milkweed (Asclepias viridis) which look almost identical to common milkweed at various stages in their lifecycles except for a few key distinctions:

Showy milkweed is usually a bit shorter than common milkweed, maxing out at around 3′ tall. Showy milkweed doesn’t produce giant flower clusters like common milkweed, but each individual flower is larger and more crown-shaped than common milkweed flowers. Showy milkweed also doesn’t seem to spread nearly as aggressively as common milkweed. 

Showy milkweed shoots, young leaves, flowers, and young seed pods are all edible. The vegetative parts are best cooked before eating. 

Spider milkweed maxes out at about 3′, so it’s usually a bit shorter than common milkweed. The leaves are smaller with wavier margins, relative to common milkweed. Spider milkweed also bears large round flower clusters but the flowers are much more uniformly white with green accents, relative to common milkweed flowers which are pink with white accents.

(PFAF lists the edible parts/uses of spider milkweed.)

Not all milkweed species that look similar to common milkweed are edible and/or taste good. At different stages in their life cycle, it can be very difficult to tell different milkweed species apart. Eating a poisonous milkweed is not advised, so make absolutely certain you’ve positively identified your milkweed species prior to eating it, whether it’s growing in the wild or growing in your garden.  

You should also only harvest edible milkweed from spots that haven’t been sprayed with pesticides. Given the common practice of municipalities and power companies spraying herbicides along roadsides and under power lines coupled with landowners and farmers spraying herbicides to maintain monocultures or manicured landscapes, this may be difficult to accomplish.

Ubiquitous use of herbicides and other types of pesticides is one of the primary reasons for both the decline of milkweed in the wild and the species that need milkweed to survive, such as the Monarch butterfly. 

Poisonous lookalikes to Common milkweed 

If you plan to forage Common milkweed in the wild rather than growing your own, you should beware of the fact that it has a poisonous lookalike: Apocynum cannabinum, commonly called dogbane.

The bad news from an identification standpoint: both species grow in colonies, produce a white latex sap when cut, and the leaves look almost identical. The good news (or more bad news?) is that dogbane is supposed to taste terribly bitter, whereas a food-quality Common milkweed which hasn’t hybridized with another species is not bitter.

However, rather than trying to identify dogbane by nibbling on a poisonous plant, we’d advise you to use your eyes, not your taste buds. The easiest visual distinctions between Common milkweed and dogbane are: 

Leaves: The underside of dogbane leaves are smooth, whereas the underside of Common milkweed leaves are velvety/slightly hairy.

Stalks: Dogbane stalks are smooth and turn red/brown when mature – they’re also solid when cut. Common milkweed stalks are slightly fuzzy and remain green at maturity – they’re hollow when cut.

Branches: Dogbane branches as it matures. Common milkweed does not. 

Flowers: Dogbane forms small, relatively thin flower clusters with white and green flowers. Common milkweed forms dense round flower clusters containing pink/purple flowers with white accents.    

Fruit: Dogbane forms long thin pods that look like a pointy bean pod whereas milkweed forms fat, spiky pods that look like overweight okra having a bad hair day. 

How to eat common milkweed 

Now the good part… If you’ve made it this far, we can safely start talking about how to eat the various edible parts of home-grown or wild-foraged common milkweed! 

First, a quick repeat of the warnings at the top of this article: 1) don’t ever eat a plant you haven’t 100% positively identified and know to be safe (common milkweed has poisonous lookalikes), 2) eat any new plant/food sparingly until you know you won’t have a negative reaction to it, and 3) if you’re pregnant, nursing, or taking medications, consult a qualified medical expert prior to eating any new food to make sure it’s safe under your particular circumstances, e.g. there are no contraindications.  

A. How to eat common milkweed shoots

Similar to asparagus, you harvest and eat the tender young shoots of common milkweed as they begin emerging from the ground. Here in Agricultural Zone 7b, our common milkweed shoots reach an ideal harvesting size starting in early to mid-April. We also harvest shoots from later-season runners growing in unwanted spots (like our walking paths) well into the summer months.  

Milkweed shoots can be harvested at various sizes, from a few inches tall up to about 8 inches. You can remove the lower leaves to cook separately (for more of an asparagus-like look) or leave them on the shoots. Cook common milkweed shoots as you would asparagus — you may be surprised that you like their sweet, mild flavor even more than asparagus.

Your first time trying common milkweed shoots, we recommend something simple like steaming or a simple pan sauté in butter (or EV olive oil) with a sprinkle of salt. That way, you get to know the basic flavor and qualities. 

B. How to eat common milkweed leaves

First thing to note when harvesting milkweed leaves: look for Monarch eggs and caterpillars on the tops and bottoms of the leaves prior to removing the leaves from the plant. If you see eggs or caterpillars, don’t harvest the leaf — or move later 3rd+ instar caterpillars to older, less tender leaves. (Younger caterpillars may not be able to chew more mature milkweed leaves.) When in doubt, defer to the species most likely to go extinct. 

Of all the edible parts of the common milkweed plant, the leaves yield the largest harvest. They also happen to be one of the best cooked greens we’ve ever had. Their flavor is unique, but if forced to describe them we’d say the leaves are like a cross between spinach and stinging nettle: sweet with umami notes.  

Common milkweed leaves should be harvested when they’re young and tender. Don’t eat the older, mature leaves. Like other parts of the plant, the young leaves are wonderful in omelettes or egg dishes. Or just lightly sauté them in a pan until wilted with butter (or EV olive oil) and a sprinkle of salt.

We also find it helpful to pour in a bit of water and cover with a lid for a few minutes to steam the leaves before finishing with the lid off. This minimizes the amount of butter or oil you have to use while allowing the leaves to fully cook without charing too much, thus preserving their flavor.  

A lot of foraging guides and online resources recommend repeat boiling (with corresponding dumps of water) of milkweed leaves prior to consumption. However, this process is unnecessary for safely eating common milkweed and likely originates from an incorrect plant identification in an old foraging manual. Not to mention, boiling any vegetable for long periods of time significantly reduces its water-soluble nutrients, leaving behind a mushy flavorless blob. Not a great eating experience. (And one of the reasons we don’t bother with pokeweed.) 

A light ~1 minute boiling before sautéing? We’re ok with that. 

C. How to eat common milkweed flower buds 

As the weather warms and your 2+ year old common milkweed plants reach 3′ in height, they’ll start to make flower buds that look pretty similar to broccoli florets. Once you have a mature colony, you should harvest and enjoy some of these flower buds.

Start with a simple pan sauté in butter (or EV olive oil) and salt to enjoy the flavor, before moving on to more complex dishes. (See note in leaf section about adding water and covering with a lid, which also applies here.)

Another suggestion is to pickle common milkweed buds to make a caper alternative. Keep in mind that harvesting all the flower buds on your plants would mean no flowers and no immature pods/seeds/silk. A travesty that should be avoided. So harvest buds lightly, unless you have a bountiful quantity available, which we do not since we have only what’s available in our garden.

D. How to eat common milkweed flowers

We love edible flowers. Common milkweed flowers smell incredible, rivaling invasive Japanese honeysuckle for best fragrance. Their taste can be equally exquisite. 

One thing we’ve noticed: common milkweed flowers’ flavor varies pretty dramatically as they develop. At peak when they’re upright, bright in color, and firm, they’re literally dripping with nectar and taste candy-sweet. Pick them too early or too late and they’re rather dull. You’ll get the hang of when to pick the flowers with experience. 

Yes, we eat common milkweed flowers raw. Thus far, we’ve only eaten small quantities when we’re out in the garden and haven’t done anything exciting with them in the kitchen. If you want a common milkweed flower recipe, use our standard fermented wild flower cordial recipe, and simply substitute common milkweed flowers.   

E. How to eat common milkweed pods

Young common milkweed pods are one of the best veggies we’ve eaten. Emphasis: young. Too old and they turn unpalatably fibrous and even bitter.

When should you harvest common milkweed pods? Foraging expert Samuel Thayer (you’ll want to get his books) recommends harvesting the pods when they’re no more than 1 3/4″ long. At this stage, the pods aren’t fibrous and the silk and seeds inside are still soft and white. 

When giving them a light squeeze, you’ll notice that they’re still firm to the touch. Once they start to feel soft and almost balloon-like, the outside is likely too fibrous to eat, but the insides may still be great for eating. 

If you’re in doubt, slice open the young pod along the visible line that runs the length of the pod to have a peek inside. If it’s all-white, pop out the white center, discard the fibrous green outer skin, and you’ll soon be enjoying a delicious treat. 

Steam and/or sauté the pods as detailed above in the leaf section. The young pods are delicious all on their own and shouldn’t be adulterated. (You’ll enjoy sweet vegetable flavors from the pod combined with savory umami notes from the seeds/silk inside.) Slice them into pieces like okra prior to cooking or cook them whole – they’ll taste delicious either way.  

F. How to eat immature seeds and silk of common milkweed 

Once the common milkweed pods hit 2+ inches, they’re likely to be too fibrous for eating. However, the immature seeds and silk inside are still delicious if they’re still fully white in color.

Exactly how long the insides are good for eating is difficult to say, but so long as the white part is still juicy (not dry and fibrous), you can continue to eat it. To harvest, cut the pod along its line and pull out the white centers. Eventually, the seeds and silk will develop into their characteristic fluffy, cottony texture and be better for toddler toys or stuffing pillows than as a food.      

Some foragers consider the white, immature seeds and silk to be the best culinary treat the Common milkweed plant has to offer. When cooked, the texture is surprisingly similar to melted cheese and rich in flavor (your hands will smell like cheese after handling).

Given their seasonal overlap and flavor characteristics, we have plans to make a chanterelle-milkweed silk risoni (orzo). If it turns out well, we’ll share the recipe. (Update: It turned out wonderfully! See recipe: Orzo with chanterelle mushrooms and common milkweed.) 

Question: Will eating your milkweed take food from Monarch butterflies? 

Regenerative agriculture takes place on both a small and large scale. Your yard or garden may be small, but it can be a regenerative agro-ecosystem. 

That’s a fancy way of saying you can build healthy, carbon-rich soil teeming with life; provide habitat for birds, reptiles, amphibians, insects, and other critters; and still produce delicious, healthy food for your kitchen table. Human habitation doesn’t have to degrade ecosystems — it can’t be if we want to live up to our name, Homo sapiens (wise man/woman), while continuing to provide a habitable planet for future generations.

Growing common milkweed an an edible crop for you and Monarch butterflies is a perfect example of this philosophy in action. The milkweed you don’t grow will never be a host plant for Monarchs. 

And since you don’t eat milkweed like a carrot (e.g. removing the entire plant at harvest), there will be plenty of milkweed to share with Monarch caterpillars and other insect species. Depending on where you live and what generation of Monarch tends to show up looking for a host plant, you may also find that strategically cutting down some of your milkweed at a set time is a helpful approach…  

Why? Milkweed rhizomes will produce new shoots when you cut down old ones. Since the new growth is tender and easy for small caterpillar mouth parts to chew relative to older tougher/fibrous leaves, these younger plants will be favored as egg laying sites. 

And now you know how to eat your Monarch butterfly garden in partnership with Common milkweed.    

KIGI,

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