What Did Black Swallowtails Eat Before we Brought In Parsley, Dill, and Queen Anne’s Lace?

Black Swallowtails

Black Swallowtails in the Butterfly Garden

Last week I used a photo of a Black Swallowtail Butterfly in a post, which prompted one of my favorite Ecosystem Gardeners, Cindy Brown Ahern, to post this comment on Facebook:

This is such a beautiful creature, and YOU can do something as simple as planting parsley, dill, fennel, carrots in your garden to provide a food source for the caterpillars in addition to flowers to provide nectar for the adult butterfly!

Carrots, Parsley, Dill, Fennel, Queen Anne’s Lace: not native

And this is a very true statement, Black Swallowtail caterpillars do, indeed, use all of these  as host plants. But I started to wonder what these caterpillars ate BEFORE the European settlement when none of those plants were present in this country.

So I started to research this question. I paged through all of my butterfly gardening books, but each and every one of them said the same thing: “Black Swallowtails use members of the carrot family (Apiaceae) including parsley, fennel, dill, Queen Anne’s Lace, and carrots.”

Same story online, even at native plant society pages.

So, What IS Native?

Now I am nothing if not determined, so several hours later I FINALLY found the answer at the Lady Bird Johnson Wildflower Center. They have an amazing plants database which is searchable by plant family.


I searched on Apiaceae and discovered that there are 82 native members of this family, many of them endangered.

But, not all of them stated that they were a host plant for the Black Swallowtail. So I entered “Black Swallowtail host plant” into the search box and ended up with three species:

  1. Zizia aurea (Golden Alexander)
  2. Polytaenia texana (Texas Prairie Parsley)
  3. Polytaenia nutallii (Nuttall’s Prairie Parsley)

This is a great start!

What to do now?

I am not suggesting that you stop planting parsley, dill, or carrots for the Black Swallowtails in your butterfly garden, but fennel can be a little aggressive in the garden, and Queen Anne’s Lace is invasive in many areas (but is a main ingredient in many wildflower mixes which I call “meadow in a can”), so I’d avoid both of those.

AND, if any of the above native plants are appropriate to your site, add them to your garden.

ALSO, plant some of the other 82 native Apiaceae species and watch them diligently. If you notice Black Swallowtail caterpillars on any of those plants, take a photograph and send it to the Lady Bird Johnson Wildlflower Center. It may very well be that we have lost some knowledge of host plants for this butterfly.

And please let me know here if you notice Black Swallowtails using any of these plants. It would be so exciting if we could regain the knowledge we have lost in this area.

Go to the Native Plants directory to see if you can find a local supplier of these natives to add to your garden in the spring. Now is a great time to plan for this addition to your butterfly garden.

If you can, please support the Lady Bird Johnson Wildflower Center. They do amazing work.

Here’s some natural history information on Black Swallowtails with a range map so you can see if you could have these beautiful butterflies in your garden.

Do you have any of these plants already in your garden? Please let us know if the caterpillars are using them.

More information about Black Swallowtail Butterflies:

Check out my new free online course Ecosystem Gardening Essentials, 15 free lessons delivered to your inbox every week, teaching you to garden sustainably, conserve natural resources, and create welcoming habitat for wildlife in your garden.

© 2009 – 2013, Carole Sevilla Brown. All rights reserved. This article is the property of EcosystemGardening.com If you are reading this at another site, please report that to us

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  1. says

    This is great information. I’m pleased to see that black swallowtails have been seen in my part of Kansas. I do have parsley in my garden but I’ve not seen any black swallowtails. I’ll have to check whether any of the host plants are native to my area and see if I can add them when I’m putting new perennials in the garden.
    .-= Alison Kerr´s last post ..Foiling Squirrels At Your Feeders =-.

  2. says

    I have only ever seen Black Swallowtails on dill in my MA garden, but my Caterpillars of E. North America (Wagner) book says that they also feed on Rue and other members of the Rutaceae family. Good point though, asking ‘what did they eat before colonists brought carrots, parsley, dill, etc to this country’? Many of our butterflies have adapted to human settlement and succeeded because we’ve given them lots of what they need to survive. Brings up a philosophical question whether it’s a good idea to remove all non-natives from our gardens and stick with strictly natives. We’ve enabled these butterflies to prosper, is it fair to take away what they are used to?
    .-= Ellen Sousa´s last post ..Guest Posting at ConservationGardening.com =-.

  3. says

    Thank you for this excellent information. I have always sacrificed my dill to the swallowtails, but never noticed them on any other plants – and I do grow carrots and parsley. There is lots of Queen Anne’s Lace around so maybe that’s where they are.

    • says

      Funny story: I stopped at a farm stand over the summer and was thrilled to find caterpillars on some of the parsley. So I carefully selected all of the plants with caterpillars but when I set them in front of the cashier she about had a coronary then offered to pick out new plants that didn’t have “those worms” on them. She was totally confused when I said that I really, REALLY wanted those specific plants because of the caterpillars. Education happens at many levels……

      • Magaly says

        I did that too at my local Home Depot! They had Milkweed plants on sale. Monarchs were flying around all over them. I started searching for plants with caterpillars. Someone came over to help me find a “good plant”, with no bugs! I explained I was actually looking for the biggest caterpillars I could find. He was really confused but let me pick all the caterpillars I wanted. That was a fun day.

        • says

          I sell plants for a living. I had to make a sign telling my customers to ask before removing insects from plants. Ladybug pupa and caterpillars are both things that people don’t recognize as “good bugs”.

          My father-in-law (and many others of his generation) were taught that any bug was a bad bug and all snakes should be killed.

  4. says

    Hi Carole! I recently attended a lecture on invasive plants by a horticulturist and invasive plant specialist from the New England Wildflower Society. (I can dig up his name if you like, but don’t have it on hand.) He said Queen Anne’s Lace isn’t invasive (here in MA, at least), because “it doesn’t persist in the landscape”.

    Cheers, and thanks as always for maintaining this wonderful blog!

    • says

      Michelle, I’m glad it doesn’t persist in New England. Queen Anne’s Lace is a mess here in Pennsylvania and also in Cape May, NJ. But I like the idea of adding the original host plants back to our landscapes!

  5. says

    The only plant I have ever seen my Eastern Black Swallowtail Larvae on is Florida Native WATER COWBANE (Oxypolis filiformis) which is naturally occuring in my Central Florida ecosystem. The again, I don’t offer exotics so they wouldn’t have a choice. The URL above will show a nice specimen of the caterpillar

      • says

        wellll, can’t say that it is COMPLETELY native. I only really found out about the importance of native plants in 2008 so going forward I stick to my ecosystem. I’m lucky enough to have the type of property to “go wild” with. There are non-natives there but most are naturalize. I removed all the Category I invasives and even cried since some were rather pretty…nandina was a personal favorite of mine. Alas, the rewards of seeing a passing snake, butterfly or bird knowing I was no longer being party to the demise of their habitats was well worth a few tears! Thanks for all you do and share!

  6. says

    This is great, Carole. I’ve never given this a thought. I know they eat Rue, which I have, and I’ve seen them on that, but usually it’s parsley and most of all, the dill. So far, I haven’t seen any on the bronze fennel and we have a huge clump of that. I’m kind of surprised.

    I did find another cute furry caterpillar (2 of them, actually) on the Asclepias. I’ve seen them once before and will have to look up what they are, but we don’t see them often. The only other time I saw them was in a nature preserve near here and I got all excited that I saw them. I’ll let you know what it was in Twitter.
    Kylee from Our Little Acre recently posted..Imperial Moth Caterpillars – Eat- Sleep- Poop

  7. says

    Kylee, the cute furry cats on your milkweed, are they orange and black striped and very fuzzy? I bet they are Milkweed Tussock Moths. I have them too, they usually seem to eat the older milkweed leaves, whereas the Monarch cats seem to prefer the fresh milkweed….
    ellen recently posted..Raising Herbert

  8. bec says

    Is it possible that the black swallowtail came over with some specimens of the introduced species?

  9. Leigh B. says

    My friends who conduct workshops on butterfly gardening in north Florida know these larval plants for the black swallowtail: Mock Bishopweed (Ptilimnium capillaceum), Water Dropwort (Oxypolis spp.), and Water Hemlock (Cicuta maculata). They are all in the parsley family (Apiaceae).

  10. Pudding says

    This is my first time ever doing a vegetable garden. Two days ago I found a black swallowtail in my carrot plant. I was thinking it was harm so I move the caterpillar to other place. After found that it was actually a “butterfly” and loves carrot plants I look for it next day and found it so I return her (he) to the carrot plant. I am so excited it choose my garden. I cannot wait until get as an adult.

  11. joann says

    I just found 4 caterpillars on my parsley plant that I planted with my grandchildren. We were hoping to hatch the caterpillars ourselves as a “camp grandma” project! Any suggestions?

    • says

      Some people who raise caterpillars use an aquarium with a screen lid. They put the caterpillars inside with lots of host plants (you’ll need to replace it every day) and cover it with the screen so the birds don’t eat them. It’s a lot of fun to share with your grandkids the joy of releasing them into the wild when they emerge as adults.
      Carole Sevilla Brown recently posted..Butterfly House at Albuquerque Botanic Garden

  12. Jen says

    I have black swallowtail caterpillars on my dill in my ND garden. They are also eating my parsnip leaves.

  13. Julia Vanatta says

    Watched both black and yellow swallowtails today gathering pollen on Joe Pye weed in the Peace Garden, Minneapolis, MN.

  14. says

    Nice post Carole. I use Zizia aurea in projects pretty frequently, hoping to observe some Black Swallowtail interactions. I agree with some other commenters, I see more action around the spicy herbs than the natives but I’ll keep watching over the coming years. Maybe I’ll start planting the Golden Alexander right next to the Parsley and Dill, so close that the stems and leaves end up all intertwined and the caterpillars- who were there for the annuals actually have to trip over the native wildflower, make physical contact and maybe we can jar a recognition of, “Hey, this is food!!

  15. Kathryn says

    I don’t have a website, but I can tell you that Spicebush is a native plant, and a host for Swallowtails :)

  16. S Cludius says

    A course I took on Entomology from entomologists from Texas A&M University demonstrated an easy way to raise caterpillars. They placed them in Ziploc bags and added their food to the bags. Fresh food was added every day. Opening and closing the bags daily provided the caterpillars with enough air to breath. Several little caterpillars can start out together and later be transferred into individual bags. Saves time and space. You can also place a sleeve of small mesh netting over individual plants outside to keep the wasp away. Use tooth picks to hold the netting closed between the top and the bottom and tie the top and bottom closed with string.

  17. says

    I planted several new Zizia aurea this spring and found 2 good-sized black swallowtail caterpillars on them about mid-summer. I’m sure that one was able to reach mature size, but I don’t know about the other – these were baby plants. All the plants but one have survived being eaten way back and are now putting on new growth.

    I always plant parsley for these guys, but this year the grasshoppers got to it first. I did not notice any grasshoppers eating the Zizia.
    Cynthia, aka Gaia gardener recently posted..Serendipitous Garden Combinations

  18. says

  19. says

    Here in Florida when there aren’t lush herbs growing for the black swallowtails they use native plants in the Apiaceae family such as wild chervil (Chaerophyllum tainturieri), American wild carrot (Daucus pusillis), and Mock bishop’s weed (Ptilimnium capillaceum) as host plants.

    Butterfly gardeners find it much easier to buy non-native herbs from the local garden center than locate native plants to use for their larvae. Who can blame them. Some people have the time and inclination to focus on native plant species and others don’t. Some folks just want to experience butterfly gardening without becoming activists or botanists and using dill and fennel from Lowe’s is most certainly the easiest way to go.

    That being said … local plant identification guides are a gardener’s best friend. Being able to ID natives for use in the butterfly garden saves money, maintenance, and provides the natural plants that the native butterflies use.

    Happy butterfly gardening to you all.

  20. Chris says

    I’ve come to learn this from the opposite direction. We’ve been experimenting with native plants for 5 years or so and have an expanding stand of Golden Alexanders. Today, I saw a caterpillar on one, googled, “golden alexander caterpillar” and found this page. It is a Black Swallowtail caterpillar. Exciting.

  21. Susan Wagoner says

    Today I found a fairly large Black Swallowtail larva on my “Great Angelica” plant, eating the immature fruits. I had previously noticed that the fruits were missing on the flower heads but did not know why. Now I know why. Is Angelica a native plant to the U.S. or was it introduced? I have a lot of Golden Alexander but have not found any larvae there so far. I live outside of Chicago, Illinois.

  22. Susan Wagoner says

    p.s. It was a fifth instar caterpillar that I found… is there anyway I can send you a photo?
    Susan Wagoner

  23. Molly says

    This spring I have had masses of Black Swallowtail caterpillars on my Rue plants along with the dill plants in Massachusetts.

  24. Diane Kessler says

    Watched a black swallowtail lay eggs on my zizia today! Purchased from Native Nurseries in Tallahassee FL

  25. Diane Kessler says

    The butterfly in the foreground has a blue comet flash which is the sign of a spicebush swallowtail in my neck of the woods.

  26. says

    Swallowtails ate and continue to eat leaves from the Sassafras Trees and from the different Citrus Trees, The native shrubs that also could be eaten include Spicebush plants. They really love Fern Dill!

  27. Shawna G says

    We live in Eastern Ontario and just finished raising a monarch which we try to do each year. I just found about 3-4 what I believe are black swallowtail caterpillars amongst my carrots. I didn’t even search too hard so I am sure there are way more.

  28. says

    I have been pondering this issue for quite some time. If the natural host plants of the black swallowtails are absent, it means that something is seriously wrong with the ecosystem. We should strive to restore the plants. When seen this way, resorting to non-native plants is downright crazy. It simply aggravates the situation of the native ones despite the fact that it helps the butterflies.

    It is unfortunate that we place too much concern on the charismatic species and not enough on the others. Hosts plants are just as ecologically important as the beautiful butterflies that feed on them. Perhaps this subject is worthy of an entire article.

    As I mentioned before the HOSTS website is invaluable for finding out host plants for Lepidoptera. Of course, after that, we need to find which of the listed plants are native to our area: HOSTS – a Database of the World’s Lepidopteran Hostplants (http://www.nhm.ac.uk/research-curation/research/projects/hostplants/)
    Beatriz Moisset recently posted..My Metallic Green Bees

  29. says

    Someone from the Facebook group, Gardening with Nature in Mind posted a link to this post after seeing my photos of a caterpillar, I think, a black swallowtail, on a golden alexanders plant I posted from our yard in SE Nebraska. I’ve seen a few over the last few years each year on them. I do not look for them, so there could have been more. I do also plant parsley for them, and the dill comes up each year on its own. I think I’ll start planting a bit less parsley, but I like to have enough for us to have some for cooking. I always have to inspect it before harvesting any.

    Thank you for posting this information. I did share a couple of the photos on the Lady Bird Johnson Wildflower Center Facebook page.
    Corner Garden Sue recently posted..August 2015 Wildflower Wednesday

  30. d.kenney says

    Last week I had several black swallow tail caterpillars on my dill plants, they were doing real well, and growing real fast. But yesterday, they were all got eaten by the yellow jacket wasp. The saddest this was they were eating the caterpillars right in front of me. How do I prevent should I have more caterpillars in the future. thanks

  31. Bluebird Girl says

    I have the Texas Prairie Parsley in my garden. It started growing in early spring and had already bolted and was dying by the time the butterflies started laying eggs (on my culinary parsley and fennel). I am wondering if maybe our spring was so cool that the butterflies were late. My Texas Prairie Parsley dies to the ground and returns the next spring. I was disappointed that the native plant was not used by the Swallowtails.

  32. S. Cludius says

    Last spring I discovered that I had Texas Parsley on my 15 acres in East Navarro Co., Texas. When I looked it up, I discovered that it was a host plant for the black swallowtails. I too had wondered what native plant they ate since there are lots of the black swallowtails in my butterfly garden. I knew they must be eating native plants before I planted my fennel.
    Two years ago I raised 80 black swallowtails on my porch on dill and parsley. What fun! To start with I had about 8 caterpillars; I went to a nursery to buy more parsley and dill and was given two flats of parsley that were infested with the caterpillars! What luck for me! Texas parsley is the plant on my land and so far I have not seen the caterpillars on one of them.

  33. Paula says

    Take them inside as soon as you see them, keep them in a jar and feed them fresh cuttings from the dill plants several times a day. You could alternatively take in a small dill plant and plant it inside of a large mayo jar (the industrial size)in just a little bit of soil. That way you wouldn’t have to keep replenishing wilting leaves for them to eat.

    I did this with black swallowtail caterpillars a few years ago. I got quite a few to hatch, but a few turned out to have been parasitized by wasps before I got to them. The sooner you can notice the caterpillars the better. Caterpillars often look very different when they are small than when they are almost ready to pupate. The black swallowtail caterpillars are almost all black at first.


  1. […] The Black Swallowtail lays its eggs on parsley, fennel, dill or rue.  The bright green striped larva eventaully develops into yet another black butterfly!  The male has a yellow band of color along the margins of his wings while the female has a row of yellow spots and a small band of blue on the hindwings. […]

  2. […] Let’s start with the adult butterfly, whose sole mission in life is to mate, and then the female butterfly searches for a specific host plant. Almost every species of butterfly is dependent on a specific plant (or a specific plant family) on which to lay their eggs. In this case, with Black Swallowtails, those plants are members of the carrot family. […]

  3. […] What Did Black Swallowtails Eat Before we Brought In Parsley, Dill, and Queen Anne’s Lace? “I started to wonder what these caterpillars ate BEFORE the European settlement when none of those plants were present in this country. So I started to research this question. I paged through all of my butterfly gardening books, but each and every one of them said the same thing: “Black Swallowtails use members of the carrot family (Apiaceae) including parsley, fennel, dill, Queen Anne’s Lace, and carrots.” by Carole Sevilla Brown […]

  4. […] will support a lot of butterfly life (Zizea aurea is a classic native species host plant for Black Swallowtail butterflies) and other insects, which in turn increases the carrying capacity for the birds who live in my […]

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