So, you’re wondering how to take care of your milkweed in the winter.
Good news. The majority of people will need to absolutely NOTHING to keep their plants going.
For the small portion of people that are in zones 7 or below, you’ll have to do some minor.
But it’s worth it to see these plants come back year after year- and the monarch butterfly larvae will appreciate it even more.
So let’s dive in to this quick care guide and see what needs to be done to winterize milkweed.
Last updated: 12/1/20.
Guide Contents
Milkweed in winter
The best part about milkweed is that it rarely requires any additional work to winterize.
A favorite (and vital) part of monarch butterflies’ lifecycle, the milkweed plant provides a critical food source for these caterpillars to eat.
Milkweeds are literally a “weed” that grows without the need for additional assistance.
They grow, winterize, and disperse their own seeds to propagate without any fuss.
However, if you’re living in a colder zone, you can help your milkweed plants survive the winter with some basic tips.
How to overwinter milkweed
This plant a perennial, but sadly, many gardeners trash it at the first sign of wilting.
A lot of newbie growers don’t know that milkweed can come back every year if you properly winterize the plant with a bit of TLC.
There are over 120 different types of milkweed, so there’s surely something that’s well adapted to your area. Chances are that if it’s growing natively already, it’ll do fine by itself.
But if you purchased it from seed or imported it from another hardiness zone, you can help it out if it’s not the most cold-hardy plant around.
Winter care for milkweed completely depends on your local hardiness zone and the cultivar you have.
Milkweed is native to the US, so our temperature and climate are well suited for the plant. Like most other flowering herbaceous plants, it flowers in the summer and dies back in the winter by itself.
For those in milder climates, not much work is needed to get this plant to pop up again in the spring.
They establish an abundance of roots to safely overwinter under the soil and protect themselves from cold temps all over the United States and Canada.
Milkweed is one of the few herbaceous perennials that do well in almost all hardiness zones, except those that are extremely cold.
If that’s you, here are some things you can do to protect your milkweed and overwinter it.
Block off cold by adding some mulch
Just a few dabs of mulch can protect your milkweed from cold temperatures during the chilly season.
Depending on how many plants you have, you can cover the entire plant bed or just the milkweed with some high-quality mulch.
Add 3-4” of straw mulch or regular leaves (that aren’t showing signs of rot) as an insulator to keep it from getting too cold. Cover the entire root system, which extends outwards from the plant in all directions.
Give it a good 14” diameter for established milkweed plants.
Some types of variants aren’t as hardy, like butterfly weed, so you can add some mulch to help benefit their warmth.
This extra protection can be the difference between your milkweed wilting away or staying nice and cozy.
What happens to milkweed in the winter?
Milkweed will die back and then wilt.
You can cut it back down to the stem at soil level for it to lay dormant over winter.
With proper care, it’ll bloom once again next season. If you’re in a colder area, add some mulch or row covers to protect it from the cold.
However, most people won’t have to do anything different from summer care as it has excellent cold tolerance.
Do you cut back milkweed in the winter?
You can start cutting back your plants in the autumn for the winter.
Get a clean pair of pruners and start cutting back when you notice the stems are becoming stripped of any leaves. You can cut all the bare stems straight to the soil level.
Some people like to hold off on cutting back until springtime.
This allows natural wilting and birds to come to pick up the debris that collects around the seeds for nest building.
Smaller animals may also use the foliage or stems for building warm nests over the winter.
You can totally just leave the milkweed alone and not cut it back if you don’t want to. Cutting back may help reduce the chance of plant rot or fungus and contribute to healthier blooms in the spring. But it’s up to you.
Cutting back is optional and birds will appreciate it. If you do cut back, read the next section.
When should you cut back?
You can cut back in the late fall or early spring, depending on your generosity towards the critters in your area.
If you cut too early, you’ll know because there will still be seeds stuck in the pods.
Stop cutting if you see active pods. The plant will disperse the seeds by itself, which is a critical food source for monarch butterflies!
This happens in the winter because the seeds need chill time (cold stratification) to develop properly. They’ll come off the plant and float away in your yard until the spring rolls around.
When temperatures pick up, the seed will sprout. Warm weather and water help trigger the seed to grow.
There are some species of milkweed plants that don’t need any chill time to disperse.
A. Curassavica is one of them.
Cutting back in the spring allows your plants’ seeds to disperse for all the late bloomers.
If you cut too early, you’ll kill the pod that was in development. Monarch butterflies will appreciate next year’s harvest.
Should you deadhead? Can you deadhead?
Milkweed flowers that are spent can be deadheaded in the summer.
Milkweed naturally will flower throughout late spring and early summer and then die back in the fall.
They’ll set seed in spring. The summertime is the perfect time to deadhead the spent leaves. This will help extend the beautiful blooms all season.
When you deadhead the leaves, use a clean pruner and watch out for any feeding monarchs.
Other FAQs
Here are some other common questions about milkweed that are asked by readers.
They’re not necessarily related to cold season planting only.
Where’s the best place to plant milkweed?
The ideal location should be free from cold winds and drafts with a microclimate built from artificial or natural cover.
This can be next to the walls of your home, a fence, or even rock cover. It should be available to butterflies and caterpillars with plenty of sunlight for the plant to thrive.
There shouldn’t be any excessive blockage of seed dispersal so it can propagate properly on its own
How cold hardy is milkweed?
Milkweed is cold hardy and a cold period is necessary for germination.
This is also known as colds stratification and is common in Asclepias syriaca and Asclepias incarnata. The frost tolerance of these plants are pretty decent.
Monarch caterpillars eat both of these types and exposure to cold is necessary for successful germination.
If you’ve ever collected the seeds and tried to plant them, you’ll notice that they hardly sprout from the seed.
This is because they need to be exposed to cold, which is why many experienced gardeners put them in the fridge for a short period to simulate the cold from the outdoors.
The seeds are dispersed from the pods, which will then lay dormant in the snow through the winter. So nature does this automatically.
If you want to grow from seed, you’ll need to stratify it first by letting them sit in the fridge.
Does the cold kill milkweed?
Milkweed is a cold-loving plant and it’s necessary to expose them to some degree of it.
They’re quite hardy to low dips in the temperatures and have a high tolerance to frost. A few cold snaps are fine.
It’s just the extended periods of cold you need to watch out for. Milkweed can survive ranges that dip below freezing just fine.
Zone 8 and above don’t need to do anything to protect them.
Ambient temperatures should be around 65-75F after the winter. Seeds won’t germinate above 85F.
Does milkweed come back every year?
Milkweed is a herbaceous perennial that comes back every year.
For the majority of hardiness zones, this plant will do just fine without any care.
If you have some already growing where you live, chances are that it’ll do OK without your help.
Do milkweed die in the winter?
Milkweed also dies back by itself in the winter.
Thesis normal and a part of the plant’s lifecycle.
It’ll utilize the seed pods and disperse all the seeds before the cold storm, so next season there should be new plants to feed those hungry monarch caterpillars?
Swamp vs. common milkweed care
Both milkweed varieties are similar in terms of care, but swamp milkweed will have branching stems in the center of the plant.
Swamp milkweed is also much narrower compared to their common milkweed counterparts. The stems and leaves will release white, sticky sap when cut. The leaves tend to taper at the ends.
Other than these basics, both species are excellent for monarchs and have similar overwintering processes.
Can you grow milkweed indoors?
Milkweed can be sown indoors from seed provided that the seeds have had proper cold exposure.
If you try to grow seasons that haven’t been cold stratified, you’ll find a high number of them fail to sprout.
After the seeds sprout and have established roots, you can transplant them outdoors.
When does milkweed bloom?
Milkweed generally blooms in the summertime.
Early varieties may bloom in the springtime. The plant continually will produce blooms until autumn, to where it’ll disperse seed pods for propagation.
At this point, the plant will naturally die back for the wintertime. With proper care, milkweed comes back every year since it’s a perennial.
Further reading
Here are some references you may find helpful:
- Asclepias – Wikipedia
- Common Milkweed (Asclepias syriaca L.) – FED
- Common Milkweed Fact Sheet – UMaine
Now you know how to care for milkweed over the winter
This isn’t a difficult plant and doesn’t ask for much in exchange for the glorious blooms it provides every season.
The majority of people won’t have to do anything to keep their milkweed plant coming back every year, but some can add mulch or do some basic TLC to keep their plants strong.
What do you think? Are you going to let your plant die back and grow naturally? Or are you in a colder region and need to do some work?
Let us know in the comments section below.
I took interest into microflora and microgreens before it became mainstream. The idea of growing an entire ecosystem on a tiny scale simply was astounding. That’s where I discovered that I actually like raising plants and wasn’t as much of a black thumb as I thought. Now, I’m relaying what I’ve learned to others who are getting into the hobby in a way that anyone can understand.
Thank you for the informative info regarding the Monarchs! I still have them on my Milkweed as I am commenting.
I live in the north east. My milkweed is in a pot, first time growing it. It didn’t flower or have seed pods. Should I leave it in the pot over the winter or transplant it in my flower bed? Should I move it to a flower bed in the Spring?
I grew 2 types this spring – swamp & butterfly bush. They are quite happy in smallish pots – I will place in greenhouse this year and will introduce to the outside gardens next year with protection. I am in zone 9.