Calotropis Procera

A Milkweed Tree To Feed Them All

Calotropis procera: Apple of Sodom, Milkweed tree, Rooster tree, Rubber bush, Rubber Tree, Sodom apple, Sodom’s Milkweed, Swallow-wort

Double Duty Milkweed Plant- Calotropis procera is a milkweed tree that is both a host plant and nectar flower for monarchs, as you can tell from this evidence in this picture...
For Caterpillar…and Butterfly!

Calotropis Procera Plant Specs

  • Perennial Zone: USDA hardiness zones 9a-11 (lows -6.7 °C or 20 °F)
  • Native to Africa, Arabian Peninsula incl. Saudi Arabia, Western Asia, South Asia, Indochina
  • Naturalized in warm regions including southern US, South America, and Australia
  • Annual in in northern territory of the United States
  • Full sun to part shade
  • Height: up to 15 feet
  • Spacing: at least 6 feet, 15′ for perennials
  • Flowers: maroon, purple, white
  • Velvety silvery-gray leaves
  • Blooms all season
Monarch Caterpillars love dining on the thick leaves of Calotropis procera, but the showy flowers bloom all season long and provide nectar to monarchs, hummingbirds, and more...
Dining Room Centerpiece

Calotropis Procera Pros

  • Constant blooms provide monarchs an all season nectar source
  • Large, thick leaves can sustain more caterpillars
  • Caterpillars don’t need to crawl away to pupate
  • Great option for adventurous gardeners looking to try something new
  • Fragrant flowers (unlike its wider known relative Calotropis gigantea)
A monarch caterpillar can safely form its chrysalis on the thick branches of rooster tree milkweed.
Milkweed Tree Convenience

Calotropis Procera Cons

  • Slow growth for annual zones. Faster growing Calotropis gigantea is a better option
  • Not enough data from North America – needs to be monitored for potential problems
  • Prone to aphids like most species…again, keep an eye on your plants.
  • Has been reported to be invasive in India and Africa
  • It’s non-native so plant more native milkweed varieties to support your local ecosystem (Monarchs will use both native and non-native varieties)
Calotropis procera is a lesser known milkweed that supports monarch butterflies all season long with its beautiful multi-colored blooms.
Beautiful Bouquet of Milkweed

Calotropis Procera Plant Propagation

  • Start seeds indoors 2 months before final frost
  • Seed Starting- use peat moss mix with vermiculite, perlite, or both
  • Soak seeds in warm water 24 hours before planting
  • Use a seedling heat mat for faster germination
  • Spring Sow directly after final frost (not recommended for annual zones unless you plan to overwinter)
  • Propagate from softwood stem cuttings. This also allows you to start the season with larger plants. Our plants did not flower in year 1 starting seeds.
Calotropis procera serves two purposes in your butterfly garden. It's a host milkweed plant for monarch caterpillars, and nectar flower for butterflies and other beneficial pollinators.
Starting to Seed | © Forest and Kim Starr

Calotropis Procera Growing Tips

Overwintering Calotropis Procera Indoors- have sufficient drainage from your container and keep the soil for this milkweed variety on the dry side.

After a couple months of hot summer sun and some slow release fertilizer:

Calotropis procera- this tropical milkweed variety grows well in containers with lots of sun, good drainage, and some slow release fertilizer.
Calotropis in Containers

If you don’t want new seedlings next spring, simply cut off the seed pods before they pop open or tie organza bags over them to collect  milkweed tree seeds. Seeding is not an issue for annual zones.

Open Milkweed Pod Calotropis Procera
Seeds Of Hope

Pollinator Plus:

Nature photographer Maria Firpi says to keep an eye out for hummingbirds and bees!

This section is a work in progress because there are so few North American “gardening” reports about this milkweed species. If you have experience growing procera, please comment below to shed some light on this mysterious milkweed.

note: this is not Calotropis gigantea (giant milkweed), but you can click here to leave comments on that species.

Resources:

1. Buy Calotropis Procera Seeds

2. Calotropis Procera on eBay


30 Milkweed Plant Ideas to Enhance your Monarch Butterfly Garden

Most of the photos above are courtesy of nature photographer Maria Firpi. Her blog features flora and fauna located in Puerto Rico and South Florida.
Share the Joy of Butterflies

78 Comments

  1. As stated in a post last March 2021, I have been growing Procera in my Maryland Garden (zone 7a) since 2019 in a 5-gallon pot that I overwinter indoors. I believe I got my Procera in 2019 from Accents for Home (https://www.accentsforhomeandgarden.com); however, today I see they only sell CALOTROPIS GIGANTIA – GIANT CALOTROPE. If you’re looking to buy Calotropis Gigantia as a plant rather than seed this site may be helpful. Also, you could inquire when and if they will sell Procera. Interestingly, Calotropis procera is considered a serious weed threat in several Australian regions and as a coveted milkweed plant on the mainland of the US.

  2. I’ve grown Calotropis Procera successfully in a pot for about 3-4 years in Maryland, zone 7a. I bought it as a small plant. Originally I placed it outside, full sun, not watering it much. It got a few flowers. Last year I moved it to my front porch, a part sun location and watered it when the soil felt dry to the touch. It did much better, got lots of flowers and monarchs ovapositing. In my experience it does better in part sun, not full, and prefers regular frequent watering.

  3. I live in northeast Florida.. close to Georgia border..I just purchased 15 seeds of this milkweed to grow.. hope to have great success..been raising monarchs for 4 years now and still enjoy doing it.

  4. Please, visit Florida Botanical Gardens in Pinellas County Florida. They have a beautiful living example of this lovely Shrub. I visited yesterday after a presentation by the extension service. It is filled with Cats and the Butterfly Garden itself is filled with plant after plant of wonderful delight. It gave me a renewed energy to incorporate a nice variety of plants to attract pollinators as well as for Monarchs. http://www.flbg.org/

  5. Last year, 2017, I planted the Calotropis Procera seeds and had very good germination. I only took in one plant for the winter because I didn’t have room for more. At the beginning of Feb., believe it or not, I have flower buds. I keep the plant in the worst possible area. It is 3 feet from an east window, the room is usually in the 60’s and it gets very little sun. It should not survive much less bloom under these conditions. I grow a lot of plants from seed so I am not an amateur but I can not explain this one. I have pictures but I don’t know how to send them in a comment.

  6. tony- i have 3 of these plants doing ok in pots producing many flowers but i do not notice any seed pods, is there an image or any further info on how to harvest seeds?

  7. I just ordered 25 C. Procera seeds from Hawaii, from eBay. (I know I’m about 3 months late.) I’ll probably plant 12 seeds and save the rest to replant in case of disaster, or save them for next year if the first batch grow. Just wondering how big they will get in one season? My G. Physocarpus seedlings are coming along nicely; a couple of them will soon be big enough to support a caterpillar or two.

  8. Hi Tony. I’ve been putting off purchasing one of the varieties of Giant M/W Trees until just this year. I received mine the other day, a well developed and rooted stalk about a foot tall. Not certain if started from seed or cuttings.
    I live in central NJ and understand that the Calotropis procera is not native. As the plant matures, I will attempt cuttings as a way to overwinter.
    My question concerns transplanting this plant into a large pot. I understand the soil requirements and drainage needs from other posts, but how about pot size? I would like to be able to bring the plant indoors in the winter (to see how it does).
    I was initially thinking of planting it in the ground, but I’m concerned about later transplanting to a 12-18″ tall pot in order to bring indoors for the winter. Do you have any thoughts about how this plant does when transplanting?
    Appreciate any ideas…..perhaps I should just plant it in a pot instead, but I wanted to see how big it will grow in the ground.
    Bruce

    1. Hi Bruce, If our five year plant comes back (I’m not certain whether its dead or dormant) I am going to plant it directly on the south side in full sun. Although we’ve gotten good leaf growth from it, it has never flowered. It had a good run, but never really thrived in our Minnesota garden. Females oviposited on the plant every year, but I was really hoping to see those incredible flowers first hand. Based on what hasn’t worked as well, I would definitely go with full sun, and medium to dry soil. Depending on how much it grows the first season, a 12″ pot for overwintering should suffice…good luck!

  9. Hi,
    I recently purchased a giant milkweed(Gigantea) & am having problems on the leaves. There’s a white fuzziness on the bottom, which evolves to tiny black spots & the leaf yellowing/dropping off. I’ve googled many websites, but can’t seem to find any answers. I’d appreciate any help…
    Thanks
    Pam

      1. Hi! I am looking for someone who sells the giant milkweed plant that is big enough to start flowering. Any suggestions? ??

        1. I don’t know where you live but they are selling the giant milkweed in ace hardware here in Jacksonville, Florida. Nice size too, if that helps at all, good luck..

  10. I just had very good germination from my “giant” milkweed and maybe my method will help someone.
    I soaked my seeds in a warm glass of water for 24 hrs. I put the glass on a heat pad to keep the water warm. I think that made the difference.
    I planted them on seed starter just lightly covering the seed with seed starter.
    My method of planting is a bottom layer of potting soil with food and a top layer of seed starter which has no food. The plants will be fed with no replanting for awhile. I kept the soil damp but not overly moist.
    The seeds germinated in 2 days in very low light but I’m sure a lot of light would be helpful.

  11. amazingly enough, one popped up in a pot that i thought had some dahlia bulbs in it outside, it was impressive to see the rapid growth and i transplanted it to a more sunny location, i had to look online to find out what it was, i had never seen this before, your site nailed it right down, its not the tree…cant wait to see the flowers..thanks from s. california

  12. I would also like to add to my previous question. I have been doing some research and found that Milkweed needs light to germinate. I’ve kept this try inside where not much light gets to it. It’s not completely dark, but there isn’t any direct sunlight. Could that be my problem?

    Thanks,
    Adam

    1. Hi Tony,

      Somehow my original message never got through. I will retype it.

      I received Calotropis Procera seeds from smartseeds a few weeks ago, soaked them in water overnight, and planted them. I used a green house with Miracle-Gro seed starting mix and kept the seeds warm and moist with a heat pad. Around 78-80 F. It has been 3 weeks and I have seem absolutely no germination, so I dug the seeds out and to my surprise, the seeds were just sitting there. They were moist, but there was absolutely no root growth or signs of the seed opening. They still look like very healthy seeds however.

      My container was positioned underneath an awning where there was no direct sunlight. Could that have been my problem to the seeds not germinating? I put the seeds in a plastic bag just now to see if they will germinate in there.

      Thanks,
      Adam

      1. Hi Adam, I would definitely try something different at this point, so putting the containers in direct sunlight sounds like a good idea…good luck!

        1. Hi Tony,

          I put some seeds in a plastic bag and put them out in the sun. Now there are some roots coming out of the top of the seeds! I put the seedlings in the soil pods so they can grow better there. Not having mold in my greenhouse signaled something was wrong. Top of the soil is green now but I’m getting good germination.

          First time growing milkweed from seeds.

          Thanks,
          Adam

          1. calotropis procera has pretty good germination rates with fresh seed. I’m sure it will prefer your growing conditions down south…good luck!

  13. Hi Tony,

    I bought some Calotropis Procera seeds a few weeks ago from smartseeds. The seeds looked very healthy and were not damaged in any way. I soaked the seeds in warm water overnight. Then, I planted them in a plastic greenhouse with the hexagonal pods and used Miracle-Gro seed starting mix to get them going. I also used a heat mat underneath the soil to keep the seeds at around 78-80 F. The greenhouse was kept warm and moist for 3 weeks.

    I planted 4 seeds and have seen absolutely no germination. After 3 weeks, I removed some of the soil and tried to find the seeds to see what they were doing. To my surprise, after all this time, the two seeds I dug up have just been sitting there the entire time. No roots, no sign of any germination. The seeds were moist and warm when I dug them up. Just now, I put the seeds in a plastic bag on a wet paper towel to see if that will work.

    It’s a bit frustrating for me to wait all this time just to find the seeds just sitting there. The soil was kept moist and the temperature never got below 65 F. The temp dropped to 65 F one night because my heat mat got unplugged and I had to keep the tray outside.

    Any ideas as to what might have happened? Do you think just a small dip in to the mid-60s temperatures could have destroyed my seeds? They look perfect as of now. Do you recommend I try the remaining 6 seeds?

    Sorry this can be a bit frustrating but I hope you have some ideas as to what may have happened.

    Thanks,
    Adam

    1. Hi Adam, germination should only take a few days. I soak them in water overnight, plant the seeds in a tray (with dome) to trap humdity. I use a regular seed starting mix without fertilizer. The seeds typically start germinating in about 4 days. I don’t think one night without the heat mat would make a difference. Were you adding more water to the soil? Conditions could have been too moist…

  14. Update on my C. procera plants:

    Out of 11 that were started from seed last spring, only three plants have survived to this point. They are planted in a heavy, water retentive mix that I concoct to help reduce water usage here in drought stricken SoCal. Generally works well in my container butterfly garden, except for C. procera. I lost 8 plants over winter to too wet of a soil mix. When the remaining 3 grow sufficiently fast with warmer weather, they’ll be potted up in a much looser, faster draining mix.

    BTW, Tony: one of the 11 started last spring bolted and grew like Jack’s beanstalk. It produced flowers by mid to late summer last year, but set no seed. I’ll try taking cuttings this season if all goes well.

    1. Thanks for the update, our C. procera plant is much happier in its new container with improved drainage. When I went out the soil almost looked dry! I think this may be the year our plant finally flowers. I look forward to your procera updates this summer…thank you!

  15. Reporting back one year after my previous/first post. C. procera (seeds from Hawaii via eBay last Fall) seemed very fresh and all germinated. Grew healthily (but slowly) indoors under artificial lighting, in quick-draining gritty media as well as mineral wool cubes. Tried several times to pinch or even cut to “ground” to encourage bushier growth – and sometimes did get a second branch to grow for a while – but it would eventually lose it’s leaves and wither. For me (indoors in winter and spring, at least) this was a stubbornly apically dominant plant.

    Was able to move a couple to small outside containers in early July – and they’ve done super in the sun. (Even a transplant into a more standard / more water-retentive peat-based mix.) I thought the leaves were big when growing indoors, but outside they’ve been growing to about 8″ long and 4″ at their widest.

    Cats hatched on and initially feeding on Tropical MW easily transferred to the C. procera, quickly starting to eat. (Even have switched some back and forth.) Note the leaves are thicker too – and may be crunchier – as the munching sound is even louder than with Tropical or Common.

    Hope this may be useful to others.

    Thanks for maintaining this great site, Tony. It’s a wonderful resource.

    1. Thank you Ashley…first-hand reports from other butterfly gardeners are always helpful! Our remaining procera really took off in the sun this season too! It did not flower but the leaves are huge. Definitely a full-sun variety!

      I did see a couple of caterpillars on it, but they got picked off by predators. I think this is a tougher variety for them to chew because the leaves are so thick. Hoping for our first blooms in 2016…

      1. My thanks to everyone who has posted comments regarding your growing experiences with this plant.

        Tony, when did you first transplant your newly germinated Calotropis procera seedlings? I just pricked two seedlings that haven’t even shed their seed covers and the root was very long, much more than I expected. I put them in little root pots but I’m wondering if I should have transplanted them into deep pots to begin with? I’ve read this plant develops a deep taproot and doesn’t transplant easily.

        All comments are appreciated.

        Mary

        1. Hi Mary, I transplanted our remaining procera plant to a different pot this fall because it was retaining too much moisture. There wasn’t a long tap root, but that could have been the growing conditions it was in. If you plan on keeping it in a pot during the season, I would opt for a larger size.

          As for transplanting, milkweed is generally difficult to transplant because of taproots, but it can be done and I’ve had success with native varieties over the past few seasons:

          Transplanting Milkweed with Taproots

          1. Thank you for the helpful links, Tony. May I ask how old the little seedlings were when you transplanted them from their seed starter cups into a larger pot?

            Do you do it as soon as they germinate or do you first grow them for a bit in the starter cups?

            Mary

          2. Hi Mary, I’m not sure if this matters? I typically transplant milkweed from starter trays after it has a couple sets of true leaves. I’ve never had any issues transplanting small seedlings…

            I have some procera seeds I’ll be starting in water to see how effective this propagation method is. I will be sure to add more info when I get the results…

  16. Hi,
    I am looking for the leaves of Calotropis procera , if any one has any idea how can I get the leaves please let me know. Thanks

  17. Hi Tony-

    I recently purchased C. procera seeds from Mia Myers, owner of SmartSeeds. She sells 10 seeds for $3.99. I received them within a few days, all 11 seeds plump, clean, and healthy looking.

    The seeds are planted indoors in peat containers filled with a commercial peat/perlite mixture inside a plastic mini greenhouse set on a heating mat, with t5 grow lights suspended above and placed next to a sunny window. Can’t wait to see my little babies sprout!

    I live in a mobile home park in SoCal whose tiny yard consists of cacti and succulents with decorative gravel and some well placed rocks. My butterfly garden is all growing in various sized containers, so I feel that C. procera may be a challenge size wise. With periodic plant and root pruning, it should live long and prosper (tribute to Leonard Nimoy) inside a large pot.

    I’ll keep you posted as to how they are doing. My USDA zone lies between 9a/9b, so they should last at least to the next real cold snap (For my region; not even comparing to yours! ) for my area. The Gomphocarpus physocarpus plants I have made it past a couple of 28°-29° frosts we experienced here. Hopefully, C. procera will fare as well.

    1. Hi Crunch,

      I bought seeds through her on eBay a while back and all 10 of my seeds sprouted so hopefully you will have the same success. In Minnesota are physocarpus is the last milkweed variety that goes down each season. Of course, it doesn’t come back here so we overwinter indoors. Keep us posted on your procera seedlings!

      1. Hi Tony-

        Update on the C. procera seeds: as of today, all 11 of them have germinated. The first few germinated within 4 days, which really surprised me, as I figured the first to pop up wouldn’t be until at least day 7. Gotta love these kind of surprises!

      2. Update on the C. procera seeds I germinated: All are growing well and quite vigorously. My tallest one is about two feet tall and still reaching. I do hope it will take well to a large tub for its home, as I have nowhere to plant it in the ground where I live.

        1. Our procera did very well in a large pot this season, but still did not flower. I did find several eggs and caterpillars on it again this season. Thanks for your reports and good luck with your procera containers!

  18. I wanted to let everyone know that my seedlings are about 12 inches tall and monarch caterpillars love to munch on them. I know have Monarchs laying eggs on them and cats going into chrysalis on one!

  19. I just bought 2 acres next to my house in White Bear Lake MN. I saw a monarch in my garden last summer. I want to plant a garden/trees on the property for monarchs. The soil is not great. Can you recommend a) what to plant and b) anything I can do for the soil?
    Thanks very much for any help anyone can provide
    Betsy Larey

  20. Is there a difference between a giant milkweed and a giant milkweed tree? This weekend a seedling of a giant milkweed was gifted to the Waystation, but I haven’t had time to really research it. I’m wondering if this is what it is or if I’ve got a different plant.

  21. Just a quick update ….I started mine in July 2014 from seeds…..I am down to 6 plants….. they are all approx. 6-8 inches tall…..they are in either corrugated garden bins or pots……two of them have had Monarch cats nibble on them a bit…..I have had a few aphids on one……they are doing well and definitely add character to my butterfly garden!

      1. so far no sign of any blooms – could be that that monarch cats are eating the leaves too quickly!

        1. Hi Sharon, I’m not sure if you will get blooms in year one, but to have any chance I would transfer caterpillars to other varieties if possible.

  22. Hello,
    the link above leads to seed for Calotropis gigantean not the proceia variety. could a source for the Proceia be posted

    Thank you

    1. Hi Vernon, the only source I know for procera seeds is currently sold out. I link to ebay because there are so many vendors that sell seeds through them (both businesses and gardeners), that it’s only a matter of time before procera seeds are listed again. Please check back…

      1. I purchased seeds about a year ago from smartsseedstore in Claremont, Ca. I seldom had caterpillars on mine feeding. The flowers are beautiful. Maybe this year Monarchs will lay eggs on my two plants that are about two feet tall.

        1. We have gotten eggs on ours the past two seasons in Minnesota. The first year on tiny seedlings and last year on plants a couple feet tall. This is with lots of other options in the garden…I was afraid the Minnesota monarchs might not know what it was!What type of pollinators are you attracting on the west coast with this variety?

    2. I’ve just ordered procera seeds on Amazon @100/$5.00 Shipped from Guadalupe in the West Indies. Monarchs overwinter in my area on naturalized eucalyptus trees. Their ability to find host plants is amazing but not extraordinary for hexapods.

  23. I would like to know how to start Giant Milkweed from cuttings, I just came back from Puerto Rico and brought 4 cuttings, about 5″ back, I put them in water, but how do I go from here? I live in Nothern Virginia, so if I get them going they would have to go into pots, not a problem, since I have a greenhouse to overwinter them in, I just need to know what the next step is and if it possible to grow them from cuttings
    Thanks.
    Inger

    1. Hi Inger, the only people I’ve spoken to that have had success rooting giant milkweed have used rooting hormone powder and planted directly in pots filled with organic peat. You need to stake each cutting with something like a small wood stake and attach with a twist tie so the cutting stays upright while it establishes a root system. good luck!

    2. Hi there,
      I live in Hawaii and have over 100 pots of these plants. We call them Crown Flower plants and make lei with the flowers. After soaking the cuttings for a week or two, dip the end of the cutting into a rooting hormone and plant in potting soil. I have about a 75% success rate in growing the plants in my butterfly garden.

      I hope this helps!
      Darlene

      1. Thanks Darlene…propagation tips are very much appreciated for these “newer” milkweed species. I will definitely be trying out your propagation technique on our established plants this season.

      2. Hello. I need help. Can the Giant Milkweed be planted near a drain field or septic tank? How long is its root system? Are the roots invasive? I’m concerned about the drain pipes. Thanks.

  24. I just started some indoors in Oregon. We only have two months of sun left so this is poor/impatient planning on my part but what the hey. I will baby them all winter and put them outside next year when our rains stop.

    1. Hi Josh, I think your plant may work out for the best. If you get them going over winter, they could flower for you next season. good luck!

  25. Looking forward to more info on these.

    Has anyone grown either of the “giant” milkweeds (Calotropis gigantea or procera) totally indoors under artificial lighting? – Would have to grow something like this indoors here all year around…

    It sure sounds like the huge leaves of Calotropis might make things easier as an abundant host food for monarch cats. (One Calotropis vs several tropicals to deal with…) But wondering about container size, and how fast they grow/keeping the “tree” size manageable (pruning).

    1. Ashley, I don’t know anyone else that grows these in pots so we are the guinea pigs! The only one that died indoors was in a pot with poor drainage. Two more died outdoors during our wet spring.

      They have grown like molasses in Minnesota, but hoping the big one will flower in August. The reason I wanted to try procera is because it’s both host and nectar plant. We have gotten several eggs on it this season. I am bringing in both of ours over winter again…

      Your vision of ‘one tropical to feed them all’ sounds much more feasible in Florida. Please keep us posted!

      1. I will be growing this next year for the first time. I will have ~ 20 types of milkweed next year and am also considering Calotropis gigantea. Am wintering over 7 Tropical MW under lights in the basement.

          1. Hopefully next year 🙂 I got a late start this year and only had 5 plants total of 3 types. Also I am in an urban area and there are NO milkweed plants near by that I have seen.

    2. Ashley,
      I started with 3 inch tall plant in April 2014 in my greenhouse planted in a one gallon pot. It quickly outgrew that pot so put into a 5 gallon. Now it is over five to six feet tall! It almost reaches the top of my greenhouse, it has bloomed nonstop and the caterpillars love it. I live in the high desert, in the winter it can get well below freezing. I will keep it In the heated greenhouse over the winter and cross my fingers. I love this plant/tree?

  26. I just received some of these seeds from Hawaii and will let you know how they do! I am in Florida !

      1. I soaked my seeds overnight and planted them Sunday. I already have two seeds sprouting! Fingers crossed ……

        1. I have 16 sprouts now! Wow! This sprouted amazingly fast! I plant to keep all of them potted and on our porch until our last frost in February of 2015. I have never seen one of these trees. I will plan my butterfly garden around these trees. So exciting! A tad tired of the tropical milkweed here in FL.

          1. do you have any more of these? I live in Florida too. I have so many tropical milkweeds and one giant milkweed plant but no seeds from it. I am not sure if its the same plant as yours. Mine isn’t called a tree?? Let me know thanks.

            Christina

          2. Hi Christina, Calotropis gigantea (giant milkweed) may be what you’re growing. That is more commonly sold in nurseries throughout Florida. If you can’t find “procera” locally I would try seeds. good luck!

    1. Hi Sharon, I just ordered the Procera seeds from Hawaii. Any suggestions? Thought I’d plant in 5 gal pot – makes it moveable and no ground space. Live in So Cal.
      Denise

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