Showy Milkweed for Western Monarchs
Asclepias speciosa common names: showy milkweed, showy butterfly weed, creek milkweed, Greek milkweed
Asclepias Speciosa Plant Specs
- Perennial Zone: USDA hardiness zones 3a-9b (lows -39.9 °C or -40 °F)
- Native Plant: western half of US and Canada ) Az, Ca, Co, Id, Il, Ia, Ks, Mi, Mn, Mo, Mt, Ne, NM, Nv, ND, Ok, Or, SD, Tx, Ut, Wa, Wi, Wy, BC, Ab, Sk, Mb)
- Full or almost full sun
- Height: 2 to 6 feet
- Spacing: 2 to 3 ft
- Foliage: large, thick blue-green leaves with fine silky hairs similar to asclepias tuberosa
- Flowers: 4-5″ clusters of pinkish/purple fragrant blooms grow at the top of the stem
- Blooms from summer to fall; first year plants may not bloom
- Seed pods: prominent during fall season
Asclepias Speciosa Pros
- Large, thick leaves can sustain more monarch caterpillars
- Monarch butterflies use a nectar source and host plant
- Low toxicity milkweed good news for pets, kids, and livestock
- Many other pollinators use as a nectar source
- Easy to start from milkweed seeds
- Sweet fragrant blossoms that fill the air
- Long bloom period 2-3 months
- Commonly found: roadside ditches
Asclepias Speciosa Cons
- Seeding can be an issue
- Prone to aphids like most milkweed
- Does not transplant easily because of long taproot
- Sometimes nibbled by rabbits and deer
- Can spread through underground rhizomes; not as invasive as common milkweed
Asclepias Exaltata Plant Propagation Methods
- Harvest Showy Milkweed Seeds in Fall and then
- Sow seeds outside in fall– November is a good option for most regions
- Divide by rhizome cuttings
- Winter sowing is a good option if you want to control plant placement
- Start seeds indoors 2 months before final frost- higher germination rate with cold stratification
- Spring sow directly after final frost
Showy Milkweed Growing Tips
- Grows more vigorously in moist soil, but it’s also drought tolerant
- Cut- At mid season after the blooms have faded, cut some asclepias speciosa stems back by about a third. This promotes fresh plant growth and could get you an extra generation of monarchs on the fresh new leaves. Leave some plants uncut if you want to harvest milkweed seeds in fall.
- Cut II- If you don’t want additional seedlings next spring, simply cut off the seed pods before they pop open or bind them shut with twist ties, rubber bands, or organza bags if you want to collect showy milkweed seeds
- Grow in full sun to insure blooms
- Transplant (and Divide) Showy Milkweed Plants in early spring or fall
Asclepias speciosa also attracts checkerspots, hairstreaks, honeybees, hummingbirds, native bees, painted lady butterflies, pale swallowtails, skippers, sphinx moths, queens, tiger swallowtails, variegated fritillaries and more… (If you know of other pollinating insects and animals, please comment below.)
Buy Asclepias Speciosa Seeds and Plants
Always purchase milkweed seeds and plants by botanical aka scientific name when possible to avoid purchasing and planting the wrong milkweed. Find the right milkweed below:
- Purchase Asclepias Speciosa Plants or Seeds from Joyful Butterfly
- Find More Showy Milkweed Seeds Here
Click Here to learn about other 30 milkweed plants for your butterfly garden.
Please post below if you have any questions or comments about growing Asclepias speciosa in your garden…
I have a lot of showy milkweed (asclepias speciosa). Everyone says the aphids should be left alone because bugs will eat them. I have found that the plant ends up getting so much black on it when I let the aphids be that I doubt it is attractive to monarchs. The flowers are discolored with black and are wilted. The plant still stands tall so is a good host for bugs, but the bees have stopped coming because the flowers don’t bloom. The only way I know to get rid of the aphids is to hose them off the plant but it’s hard to keep up with that as the plants proliferate throughout the season. I don’t want to spray pesticide or anything else that has chemicals. Do you know of a way I can get rid of the aphids?
Thanks – Jane
Hi Jane, check out these short and long term strategies for:
Stopping Aphids from taking Over your Milkweed
I’ve found this growing wild near me – Colorado Springs – and I’d like to collect some seeds but what do they look like?
Hi Joanne, here’s info about harvesting seed:
harvesting milkweed seeds
Do we cut the old blooms and will it re bloom?
Hi John, I don’t think it will rebloom after it blooms once…some people cut back earlier in spring to delay the growth cycle for later blooms. If you cut back the plants now, you will definitely get some fresh foliage.
does this have to be replanted each year or does it stay the same plant and reblooms
hi Lola, it’s a perennial plant in USDA hardiness zones 3-9
Hi Tony, I am wondering if you have any ideas about how to contain showy milkweed in the garden. We have a large pollinator garden with different types of milkweed and the showy seems to send out rhizomes which are coming up in the middle of our other plant groupings such as liatris. I am tempted to rip it all out but the leaves provide such a perfect host for the monarch eggs. Any ideas? I was wondering how deep the runners go, thinking maybe I could surround them with aluminum flashing to keep them confined.
Hi Pam, as with common, I would plant it in patches away from your main garden…you’ll want to stop it from seeding too by either cutting off seed pods prematurely or tying organza bags around them…
I love your webiste, it helped me so much during my first year of raising monarchs. Unfortunately my last one died from the NPV virus…. I cleaned the surrounding and my plants after it, although I buried it before it started “dripping” the black goo. My question is about the Showy milkweed I bought not so long ago. I live in Los Angeles and its been pretty warm, but my milkweed is all yellow and there are some black spots on it. I tried the milk spray, but still no luck. I know its the beginning of the dormant season (my first year of growing it), so shall I cut it down to the ground? And shall I water it while its dormant? Or leave it be till spring?
Hi Maximus, it’s a good idea to cut back not only because of fungus, but to discard foliage/stems with OE spores. I don’t see any reason to delay cutting back. I would network with other gardeners in your region to see if they first-hand advice/tips that have worked for them. there’s some good resources here:
Western Monarch Resources
It is now fall and my snowy milkweed is turning yellow and done for the season in Oregon. I have always went out and cut the stalks down to ground level at this time. Is this ok or recommended to do?
Hi Jonathon, you can do it now or wait until spring…
First year growing showy in central Indiana zone 5b.
Did great at first, cats prefer it above all others, but the plants died. Didn’t drop leaves, just turned dark gray, shriveled up. My question: Is this expected behavior for first year? Will the roots survive and thrive in the spring. I don’t want to grow another huge milkweed batch from seed last this spring if I don’t have to. Would appreciate any input on this. Also grew whorled and swamp. Both are doing great. Garden is all first year. thank you
Hi Belinda, common and showy milkweed can look pretty bad by season’s end, but they are generally hardy perennials. Only time will tell…
Aloha, Is it dangerous to plant showy milkweed in the islands? I don’t want to introduce an invasive species.
Thanks so much,
I’ve never heard of showy milkweed being planted in Hawaii…I would contact a master gardner program (if they have those in Hawaii?) or a local agency for more info on this.
I’d like to have A. Speciosa in my garden, but want to keep it under control. I will remove seed pods, but will ‘volunteer’ plants from the rhizomes (or the rhizomes themselves) choke out other milkweed/nectar plants even if I pull them? I am doubling my small butterfly garden and so I haven’t planted the area yet. Would spreading plants like bee balm and blue mist flower have a bigger chance next to it?
Hi Kris, if you have limited space, you might consider non-aggressive rhizome spreaders like:
Blue mist flower seeds a lot but is easy to pull and bee balm spreads a bit too.
What size of an area for just showy would you recommend?
Hi Kris, this really depends on what space you have available and how many plants you have. Just follow the spacing guidelines and you should be good…
I just bought a showy milkweed in a garden center but they said it was a water garden plant so I put it in a water garden. in its pot. is this correct?
Hi Gail, I have not heard showy milkweed called a ‘water garden’ plant before. I can tell you, I’ve grown it on the dryer side of our house and it has not thrived so we are planning on transplanting to some new areas this fall. I would try the water garden and see how it works out…good luck!
Another species that relies on Showy milkweed in my part of the country (Central Washington State) is the Milkweed Beetle, not to be confused with the Milkweed Bug. I have not had a Monarch host on it but plenty of these beetles and I really enjoy watching them. I control my Showy Milkweed by hand pulling the shoots but it is mildly invasive (in terms of a planned yard) and I am concerned about it running into my neighbors lawn in one spot. I did try pulling all the roots out on year and transplanting. The transplanting worked (not all of them though so if you try it plant a few) but the milkweed did come back where I thought I had dug it all up. Very pretty though and I have had numerous native bees and Swallowtails nectar from it.
Hi Orin, we pull both showy and common from the garden…I don’t mind doing it because they’re pretty easy to pull and both species attract monarchs and other wildlife into the garden so a little extra work is ok. Showy definitely gets used as a host plant, so keep searching!
I have some questions about speciosa. Is there any chance of the rhizomes growing under a (six-foot wooden) fence and invading the neighbor’s yard? If so, how can I prevent this? Also, is there any way to predict how tall they’ll grow? Two to six feet is kind of a wide range, and while I plan to plant them where they’ll have plenty of headroom, it would be nice to have an idea of where they’re going if at all possible.
Hi Mary, I’m not sure how deep rhizomes can potentially grow. In prime growing conditions your plants can grow to 6 feet.
I live in Tenerife Spain. I still have Monarchs flying about and many caterpillars. ( mid October ) I need to increase my milk thistle stock!!!! Seeing as it doesn’t drop below 12 degrees at night here in the winter and the days are in the 20s, what is the best way to germinate my seeds as I need many more plants as soon as possible.
Hi Susanna, all species that need cold moist stratification can receive cold treatment in the refrigerator:
Cold Moist Stratification
Bought showy seeds on amazon, honestly because I thought they were pretty.
Now, I’m reading about butterflysome and getting excited.
I am a little worried about how invasive this plant will be. Can I pot this variety?
How do I start from seeds? Now, so it’s ready for fall planting in hardiness zone 7a.
When established, can I allow nature to run its course, or should I take precautions for the monarchs to thrive.
Thank you on advanced, heather
Hi Heather, if you fall plant or winter sow, your winter weather will give the seeds a natural cold moist stratification. If you want to increase the survival rate of monarchs in your garden, you could always bring in a few to raise. Here’s more info on fall planting:
Fall planting Milkweed Seeds
Hi! I have a young Asclepias speciosa Davis that has come up finally this spring, but it is yellowing between leaf veins. Do you think I should fertilize it? I thought they liked poor soil, but I’m not sure what the problem is. I live in Sacramento, and am trying to keep my back yard in native plants only.
Hi Bonnie, we grow speciosa (not ‘Davis’) in our northern climate. It’s in well drained soil, but we amended with compost before planting. You could try removing the affected leaves and adding fertilizer. If it doesn’t grow well this season, I would consider transplanting or amending the soil in its current location…you could also transplant some to a different microclimate of your garden now and see which area the plants seem happier. good luck!
Hi, Tony: I have cold-stratified A. speciosa seeds that I’ll direct-sow in almost full sun in soil that stays moist most of the year. I live in Houston, where summers are long, hot and humid. What are the prospects for this species here? Thanks! Dave in Houston, gardeners’ hell
Hi Dave, I don’t hear much about people growing speciosa in Texas, but it’s native to your region so, in theory, it seems like a good choice. Speciosa likes full sun so I’m hopeful you will have some success. good luck! PS you might try growing some in a different microclimate of your yard to see if it thrives in different growing conditions.
HI Tony, Can showy milkweed be grown in pots? If so, how deep a pot should I use? I don’t want it spreading everywhere because I have a rather small yard and already am having a little trouble with common MW spreading through the rhizomes. I’m in IL zone 5a. Thanks and I really enjoy your website!
Hi Betsy, I have not tried growing speciosa in pots. I just transplanted some and it puts out a lot of rhizomes, so I’m not sure if it would thrive in a pot. You can always try it. However, there are other varieties without taproots you could grow in pots or in your garden. Check these out:
Growing Milkweed in Containers
I live in an apartment in Las Vegas, and am fortunate to have a large patio. Would this variety of milkweed do well in a container? My patio has both southern and western exposures.
Hi Robin, speciosa is a somewhat aggressive grower with underground rhizomes so it probably wouldn’t be one of the best species to grow in containers. You could always try a couple to see how they grow, but there are other varieties that will grow more reliably in containers:
Growing Milkweed in Containers
I planted showy milkweed plants this spring in New Mexico. I thought I had lost four out of five plants but today I found them. They are smaller than they started out but have survived. Unfortunately the bermuda (type) grass has also grown up all around them. I suppose to some extent it may have sheltered them in our windy dry climate. I wonder if I do more good or harm by trying to root it out? I could try to suppress it with newspaper mulch instead. What do you think?
Thanks so much, Felicie
Hi Felicie, if you dig deep to get the entire tap root, fall is a good time for transplanting. You might try leaving some plants and transplanting a couple others to see which area they grow best. good luck!
I have planted several types of milkweed for the monarchs migration through northern Kentucky. I have a 5 year old swamp milkweed plant and tropical milkweed that have never shown any sign of monarch activity. Last week, however, I was excited to find 5 monarch caterpillars devouring my showy milkweed. It appears, in my area, this may be a preferred type of milkweed.
Hi Linda, congrats on getting eggs on your showy milkweed. We found 5 eggs on our showy last week. It’s not necessarily always the type of milkweed they choose, but the condition of the plants at the time of the visit. Some of our showy plants weren’t looking so good early in the summer so I cut them back. The tender new growth coming back was what the monarch was probably attracted to.
Each year, you will probably find some variation in what attracts them, so it’s best to have 3-4 varieties to choose from. Enjoy the rest of your season…
I believe I saw a singleMonarch for the first time on one of two patches of ASSP I have. Normally I cut back all the stems and compost them in late summer. In so doing, I fear I might be tossing away plants that contain Monarch eggs. Are the eggs visible and when does the caterpillar form appear? The caterpillar should be easy to notice, not so the eggs, I would think.
Hi Thad, eggs and caterpillars can both be hard to see on milkweed so it’s best to check thoroughly before discarding stalks. I would wait to cut back until the migration has been through your region.
About 4 years ago, I planted Asclepias Speciosa in my flower garden in central Canada (Manitoba). It sent up more shoots and one year butterfly caterpillars completely devoured the leaves. It has spread each year but no flowers. Due to the underground rhizomes spread on this plant, my concern is will this plant become invasive to the point of overtaking a flower bed and eventually grow in my lawn. I already have an invasive problem with another plant called cluster bellflower and don’t wish to create another nightmare. Can anyone had a problem with Asclepias Speciosa (showy milkweed) being invasive? Would love to hear feedback before it’s too late!
Hi Jane, we are in our early days with this variety too. We have most of our patch in partial shade and it has not flowered either in 3 seasons. I moved some into full sun this spring to see if that makes a difference. Yes, it spreads through underground rhizomes like common. I would keep the patch separate from other garden plants. They have been easy to pull so far…
I wonder how well milkweed does as a potted plant, as I have no place other than a deck to plant things. Also, would butterflies even look for a plant that is 8 feet above ground level? I know bees do.
Hi Michelle, butterflies find nectar plants and milkweed through sight and smell…finding plants 8 feet above ground level will not be a problem…
Growing Milkweed in Containers
Hello Tony! Now that a new Spring is upon us I wonder if it is possible to start stem cuttings from Showy Milkweed or could I try to transplant young second-year plants, as they are just starting to sprout. I have two good-sized patches but would like to add another and there is some crowding in the existing gardens, plus a few volunteers where I’d prefer to have nectar plants. Any advice from anyone is appreciated as there is little info on the web.
Hi Charlene, I tried speciosa cuttings last season and they didn’t take. Stem cuttings work best for propagating tropical milkweed and they also work well with native butterfly weed. Both can be started in water.
If you have young second year plants, that would be the best time to attempt a transplant. Dig deep to get the root and make sure the soil doesn’t dry out while the roots acclimate. Good luck!
Tony, thanks for the reply. I actually took rhizome cuttings with small sprouts from existing Showy Milkweed and it appears I now have a two dozen new plants in the meadow patch. Next year I will start even more. I also have successfully transplanted second year Swamp Milkweed as the root structure is not that developed. I put them to the front of the gardens and will back them with nectar plants so collecting eggs will be easy and I can keep them cut back to control sprawling and provide fresh growth for our last generation Monarchs. Plus, the winter-sowed Butterfly Weed took off and I have about four dozen to plant in the garden and meadow. This is an exciting time of year! 🙂
I have started showy from rhizome cuttings very successfully!
Hi Stacey, that’s great news. Whenever you can start plants from cuttings it gives you a huge head start compared to seed starting. Good luck with your new plants!
I love in a townhouse and wanted to plant some milkweed in a large planter for my front patio. Do you think the milkweed will survive in a large planter? We get lots and lots of sun on that side of our home.
Hi Lisa, I’m not sure which region you live in but as long as the roots don’t freeze inside the pot and it’s big enough to support the root system, I would give it a go.
I live in CO (Denver), and I’ve only started reading about milkweed. I’d somehow gathered that I couldn’t plant it here … but, I have discovered that Asclepias-speciosa does grow in this climate.
However, I am unsure when to plant? I’m assuming seeds need to be planted in Fall … what about sprouted plants? Can they be planted in the spring?
Hi John, there are many species of milkweed you could plant in Colorado and many ways it can be propagated from fall planting seeds, winter sowing, starting seeds indoors, direct sowing in spring. You can also fall plant plants in fall or spring. You might want to check out my milkweed resources page to see all your options. There are links that go to pages with more info and also links to buy if you are interested. There is lots of info on the website that should help you get started:
How To Start a Monarch Butterfly Garden
Please avoid tropical milkweed to help monarchs. Probably OK in colder climates. The butterflies must migrate to stay healthy, if the milkweed doesn’t die the butterflies may stay too long and get sick. I think all other varieties are fine. Please plant milkweed to help the butterflies. Look on the internet for more info
I would suggest starting with these articles:
The Real Skinny on Migrating Monarchs & Milkweed
Is Tropical Milkweed Killing Monarch Butterflies?
I purchased 3 varieties for our CO climate. Unfortunately, I didn’t get them planted in the fall. What is the procedure for chilling them to plant in spring or can I plant them on a sunny day now? Also, I have a small dog…are they a problem….poisonous?
Hi Bonnie, I store mine in the refrigerator with no special treatment. Put them in a container where they’re protected in case of spills. For warm weather varieties (like tropical), I don’t refrigerate, but just soak the seeds in warm water for 24 hours before planting.
The dog answer would depend on your dog. Our dogs have never touched milkweed, and we have many varieties growing in our garden. I’ll defer to the pet experts on this one though: Animal Poison Control Info Hope this helps!
I have left my lower yard go back to nature. It is a tangle of vines, grasses and daylilies. I would like to grow milk weed next to my grassy neighbor’s field, which is cut regularly but all organic. The yard gets at lest 6 hours of sun a day. Will Milkweed grow next to a cut field or do butterflies prefer to find plants growing in a jumble of wild foliage?
I have 10 beehives and am wondering which flowering type would suit both butterflies and bees in my Maryland garden.
Hi Pamela, gardening is always an experiment and there are a variety of factors that will determine how many butterflies you will attract. Your lower yard sounds like it will be a butterfly haven as it develops. I don’t see why you won’t attract lots of butterflies next to you neighbors cut field since there are no chemicals being used.
We don’t see a lot of honey bees in our region (lots of bumble bees though) I know that honey bees like the milkweed on this page (speciosa). They also like common milkweed and butterfly weed. Swamp milkweed is a long-blooming native that attracts a ton of pollinators each summer. In our garden I’ve seen the most honey bees on non-native tropical milkweed. If you don’t want tropical in your garden, it works well as a container plant too. Those would all be milkweed varieties to check out. Here is my milkweed resources page for more info:
I received my Northern milkweed seeds some time ago. The seeds are brown so I assume Asclepsis speciosa. I am just getting around to thinking about planting them. The instructions do not say anything about a cold treatment but other things I’ve read say they should be refrigerated for 2 months. Did you folks give them a cold treatment before sending them? If not, I wish I’d stuck them right in the refrigerator when they arrived. What do you advise? Refrigerate now and germinate mid summer? Or wait until Fall to plant and let nature take care of the cold treatment? I’m in upstate NY. Thanks.
Hi Mary, all milkweed seeds are brown….your seeds could be speciosa but that species is more common to western butterfly gardens. Most milkweed species will have a better germination rate with cold treatment:
moist cold stratification
Before you plant, I suggest figuring out which species you have and asking if the seeds have received cold treatment.
If not, you might be better off getting a few plants for this season and planting your seeds directly in fall:
Fall planting milkweed seeds
you could also split them and plant some now, and some when autumn rolls around…good luck!
Hi, I have showy milkweed in my garden but I do not have any caterpillars eating them, no eggs being laid that I can see but a few Monarchs did feed on the flowers this year.
A year prior I found monarch caterpillars in my parsley but none this year. Wondering what could be wrong?
showy milkweed is definitely a host plants that monarchs use. If your milkweed is in good condition and there are monarchs in your area, they should gift you some eggs at some point. There are many factors that contribute to whether you will see monarchs or note: weather, pesticide use, garden plants, etc.. When you don’t see monarchs, take more time to improve your garden. Once they find you, they’ll keep coming back. Fall is a great time for fall planting milkweed and nectar plants!
As for your parsley, those were probably black swallowtail caterpillars that you saw. Monarchs only eat milkweed.
Last year, I had Monarch sightings in my garden from February through November, but I had quite a bit more Tropical milkweed. I’ve sought to pull out most of it, in favor of fascicularis which came back after being cut down in November. I also had a huge Mexican Sunflower all fall and don’t this year, no red to speak of to attract them. But, I thought, like you said, that they would come back. Only aphids, milkweed bugs, bees and the occasional wasp have I seen on the narrow leaf.
Hi Kaye, I haven’t tried planting that in the upper midwest, but if it’s not attracting any butterfly activity I would suggest diversifying your milkweed. Have you tried the yellow-flowered tithonia diversifolia as a perennial? It is supposed to be hardy down to zone 8. It might work out better for you, but I would check with a local nursery or gardener that grows it…good luck!
I just wanted to let you know that monarch caterpillars will eat other leaves like marigolds, & pentas. I’ve taken them off these leaves and put them back on the milkweeds.
Hi Debbie, monarch caterpillars don’t eat those plants, but could use them as a place to molt or form their chrysalis
I have a bed of day lillies from the 50’s that is many feet deep with pods. I do not discourage them because they are able to protect my hedge and moss lawn from bamboo planted 4 years ago knowing nothing about them. Soon everything planted in that part of my front yard was being invaded. I have fought the bamboo by digging up the roots and digging a trench and still it invades.
I am so happy to hear that the milkweed is difficult and spreads and moves in. Maybe it will join the day lillies. I will also add them to a sunny area in the back but the soil is far more acidic in that area because of a species of asian pine tree. Vinca has no difficulty there. I have some success here with Queen Anne Lace so there is hope.
if you are looking for a more “aggressive” spreading milkweed common milkweed (asclepias syriaca) would be a good option. I would try several species of milkweed to see if one grows best in your soil conditions.
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