How To Grow Milkweed

Growing milkweed is like giving a gift to the planet.

Here you will find WAY more info than you actually need about how to grow milkweed. It’s super easy.

Quickstart Guide

Option 1 (slow but free):

    • In the fall, get a milkweed pod that has just popped open from the side of a road or from a friend who grows milkweed. If you don’t know where to look, ask around online. Someone definitely knows. 
    • Remove the fluffy parts. Do this outside. Seriously. You will never get those freaking fluffy bits out of your house.
    • On a rainy November day, throw your milkweed seeds on the ground. Bare dirt is best. Bonus points if you toss a thin layer of potting soil over the seeds.
    • Leave that area alone for two years.
    • Ta-da! Milkweed.

Option 2 (fast but pricey):

    • Order some milkweed plugs from Monarch Watch between January and March.  If you’re a school or non-profit, they may be free.
    • When your plugs arrive by mail in the spring they will look terrible, but just stick them in the dirt. In a few weeks you will have beautiful milkweed plants!

Talking Deets

Oh ho, so you want to know ALL about how I grow milkweed? This section is for you. Brace yourself.

Which milkweed to grow:

I grow Common Milkweed, Asclepias Syriaca, in a dry, sandy soil that I never, ever, ever water. Ever. But Common Milkweed is flexible and would tolerate moist soil as well. It produces big showy purple flowers in early summer. They smell heavenly, and it grows, well, like a weed.

Monarch butterfly on purple Common Milkweed flower, Asclepias Syriaca
Common Milkweed

I also grow Butterfly Weed, Asclepias Tuberosa, another kind of milkweed, but I don’t recommend starting with it. It has beautiful delicate orange flowers that bloom into fall, but it is much harder to maintain, the rabbits love to eat it, and the butterflies will lay eggs on it only as a last resort.

Orange Butterfly Weed, Asclepias Tuberosa
Butterfly Weed

It is important to be sure you are growing milkweed that is native to the area where you live. There are over 140 types of milkweed! To get that info, enter your zipcode on the MonarchWatch milkweed market website:  Do check each variety to be sure it will grow in your yard. If I had wet soil, I would no doubt be growing Swamp Milkweed, which is very pretty and loves water.

Why poisonous is actually good:

It’s also important to keep in mind that milkweed plants are poisonous. Poisonous to eat that is, fine to handle. Don’t panic, tons of the stuff in your yard is poisonous and you don’t worry about that, do you? Few people I know live in terror of their irises, azaleas, rhododendrons, or hydrangeas. As long as you, your children, and your pets don’t eat these things, no problem. If your children or your pets are eating yard plants, don’t plant milkweed and maybe do an inventory of your flowers and shrubs to research toxicity and head off problems, yeah?

Milkweed is poisonous to us, but Monarch caterpillars thrive on these plants. Monarch butterflies lay eggs only on milkweed because the caterpillars eat milkweed exclusively- it is their only host plant. The toxicity of the plant helps them by making them poisonous to predators that would eat them. That’s why both the caterpillars and the butterflies themselves are so brilliantly colored. It is a warning. Don’t eat me or you’ll be sorry- I’m poisonous!

Where to plant:

Choose a spot for your milkweed that gets at least 6 hours of full sun a day. It wants full, bright sunlight for as many hours of the day as possible. 

Also think about things that could be toxic for the plant or for the monarch eggs or caterpillars. If you salt your sidewalks (I try to use sand, instead) the salt will be terrible for your plants if they are planted nearby. If your neighbor is a RoundUp fan, eggs or caterpillars right next to areas they spray could be at risk.

The number one problem I tend to see is when well-meaning people plant their milkweed in the front yard. The spray from the Mosquito Abatement trucks will devastate all the insects in the front yard and coat your milkweed with toxins. The backyard is also impacted, but to a significantly lesser degree. Still, I’ve signed up for notifications about when spraying will happen and I collect eggs beforehand. Then afterward I wash the milkweed extra carefully before I feed it to my caterpillars. You can sign up for Chicago North Shore notifications here:

When to plant:

Here in the Chicago area I plant my milkweed seeds in the late fall, early winter. Do not wait until the spring!! These seeds must overwinter in order to be viable. I put mine out sometime after I’ve finished working in the yard for the season so the seeds won’t be disturbed after I place them. I wait for a nice damp day before the ground has frozen solid and sprinkle the seeds directly onto the soil where I want my plants. Then I sprinkle a thin layer of potting soil, maybe a quarter of an inch, over the top.

I am sneaky about it. Since I feed the birds, they often follow me around the yard and watch what I am doing. One year, as soon as I placed my seeds, a bunch of sparrows swarmed the spot and ate them all. Poor me- no new milkweed plants that year. But also poor sparrows- since the milkweed seeds are somewhat toxic I’m sure they all had upset stomachs!

What to expect when you’re expecting milkweed:

Established milkweed plants pop up early in the spring, but I find that the new ones make a later appearance. Also, my new plants often don’t produce flowers or pods the first year and stay relatively small, under three feet. Well established plants produce many blooms and can grow to over five feet tall.

Some years conditions are not good for new milkweed. I’ll find that nothing comes up where I had planted the seeds. And then, the next year, there they are! So if your seeds disappoint in the spring, don’t despair. It’s possible they will grow the following year. 

Common Milkweed seedling, Asclepias Syriaca
Milkweed first emergence
Reemerging established Common Milkweed, Asclepias Syriaca
Well-established milkweed reemerges in the spring

Trouble Shooting

Milkweed is relatively trouble free, but there are a few things you might want to know once you have your plants up and growing.

Eventually, you will begin to notice black and orange bugs on your milkweed. Just ignore them. They are don’t bite or sting and won’t eat any plants in your garden other than the milkweed. Milkweed bug with juvenile on Common Milkweed pod  As long as you don’t get so many they are taking out your whole milkweed crop they are no trouble. They’re similar to lightening bugs, just less glowy. They overwinter in the milkweed stalks, so I just take down the milkweed stalks in the fall to protect the next year’s crop. I leave up all my other stalks and seed heads for other pollinators to use for overwintering and for the birds. For more info on these bugs, click here.

Aphids on Common Milkweed, Asclepias Syriaca
Milkweed Aphids

The other, more annoying creatures you may notice on your milkweed are Milkweed Aphids. Aphiiiiids!!!! (raises fist and shakes it toward the sky) A large aphid infestation is destructive to your plants. Also, just yuck.

I deal with aphids by keeping an eye out for them and brushing them all off with a damp papertowel as soon as I find any. That way they never get out of control. If I’m a Bad Plant Mama and I don’t notice right away, I’ve been known to just chop and toss a whole plant if it’s really covered with the sap sucking monsters. On the up side, the vast majority of years I have no aphids at all.