In this article, you’ll learn all about milk thistle (Silybum marianum), including how to grow, identify, and use milk thistle seeds as a delicious tea and medicinal plant.
Milk thistle: a pollinator-friendly, invasive weed that’s medicinal food for people
We’ve been growing milk thistle in our garden for over a decade and have come to regard it as one of our favorite pollinator plants and tea producers.
Originally from Europe and Asia, milk thistle is not native to the United States. Like many thistle species, it’s even regarded as an invasive weed by university extension agencies in some states.

Our Welsh harlequin ducks staring warily up at a spiky, flowering milk thistle plant.
Thus, special care and harvesting techniques should be employed when growing milk thistle to make sure the seeds don’t spread beyond your garden. More on that below…
26 Comments
Judy
October 15, 2024 at 4:56 pmIs there any place I can buy Milk Thistle plant? We need it or our butterflies.
Thanks so much for your interesting article.
Judy
Aaron von Frank
October 16, 2024 at 12:59 pmWe don’t know where you can buy milk thistle plants, but you can buy milk thistle seed to grow. A quick google search will yield lots of options for you to choose from. Note that you are not permitted to grow milk thistle in some states where it is considered an invasive weed, so check to see if you fall under that category before proceeding.
Cari
October 10, 2023 at 3:07 pmWe have tons of milk thistle grow on our property every year, and now I’m excited to do something with them after the bees have their turn. Very informative read. Thank you.
Susan von Frank
October 12, 2023 at 9:14 amWonderful! Enjoy your milk thistle, Cari.
Rose
July 18, 2023 at 5:17 pmHow can I use the fully bloomed purple flowers of the milk thistle?
Thanks! 🌸
Aaron von Frank
July 19, 2023 at 10:54 amWe’ve made sun tea with milk thistle flowers before, sweetened with honey. It’s not super flavorful; sort of mild and grassy, but pleasant.
Sandra
September 29, 2022 at 12:45 amWow! This has been so helpful. I want to buy milk thistle supplements but want to make sure the milk thistle is from the U.S. Do you know of any good milk thistle supplement suppliers that don’t import ingredients?
Aaron von Frank
September 29, 2022 at 12:15 pmGlad this info was helpful for you, Sandra! Since we grow our own milk thistle, we haven’t had need to dive too deep into US-based suppliers. We’d recommend first identifying a USDA-certified organic product as a starting point, then seeing if you can find information about sourcing on the company’s website. If they don’t provide that information, it may be cause for suspicion as to whether their milk thistle is sourced in the US. However, you could always reach out to their customer service to find out for sure. Hope this helps and good luck!
Eckard
June 28, 2021 at 4:17 pmDo St Mary’s Thistles always have white veined leaves
Aaron von Frank
June 29, 2021 at 7:08 amYes, white veined leaves are one of the key characteristics of milk thistle (Silybum marianum) plants, which are also called Saint Mary’s thistle.
MEGUMI EMOTO
August 19, 2021 at 7:38 pmHi! I’m looking for milk thistle plant with pink flowers on it.
Do you have any suggestions where to purchase them? I know it’s end of season but I was hoping to find it somewhere.
Thanks!
Aaron von Frank
August 20, 2021 at 12:34 pmHi! Here’s a good source to purchase organic milk thistle seed: https://www.johnnyseeds.com/herbs/milk-thistle/milk-thistle-organic-herb-seed-890.html.
Simba
May 14, 2021 at 11:46 amThere are many wild milk thistles where I live, nowadays their seeds are unripe, white and easily crush by hands, are they edible and as useful as matured seeds if I eat them? Because I have little liver problems
Aaron von Frank
May 15, 2021 at 8:08 amWild thistle seeds are edible. As to whether they contain comparable concentrations of silymarin and other beneficial compounds as milk thistle, it’s impossible to say without a scientific comparison of the seeds of various species grown in comparable conditions/environments. Like you, I also noticed some white, hollow-feeling thistle seeds on wild plants around us this year (we live in Greenville, SC) and my guess is this was due to the seeds being killed prior to maturity by a really late freeze.
Maxi Wiebe
May 9, 2021 at 6:04 pmCentral Kansas Here. I am wanting to grow milk thistle for my own medicine. Where do I buy seeds from for this purpose?
Aaron von Frank
May 10, 2021 at 9:58 amHi Maxi! You can buy certified organic milk thistle seeds from Peaceful Valley: link
donna CAVE GINN
May 17, 2021 at 1:51 pmHello, By chance this herb grows wild in Western North Carolina and I have organic seed coming in now. If you would like some seeds I would love to send you some for barter or donation small donation. Right now the plants are in beautiful bloom and will be ready to send you in a month. I will be happy to send the seed ASAP but you will have to let them dry in a paper bag. Remember this plant multiplies quickly. One plant can produce many flowers and the roots I am told will be tough to kill off. My plants started a few years ago and this year are producing fast!
I am trying to increase my income so I am testing out the product this year. Please check with your Agriculture exchange before you plant in the ground the may not want you to plant this herb due to its fast growth and nuance that it can cause. Check with Google how to plant new seeds and if you need to let them dry our first. Please reply to [email protected]
Aaron von Frank
May 19, 2021 at 12:59 pmHi Donna! Thanks for your offer. We have plenty of milk thistle seed. Grow it once, and you can collect enough seed for a lifetime – ha!
I love plants
April 28, 2021 at 11:33 amDon’t forget that the white sap is a folk medicine for skin cancers. There is def university research happening to make “official” what humans figured out for their folk medicine thousands of years ago 😀
Aaron von Frank
April 29, 2021 at 9:39 amOften times, yes. There are also some folk remedies that haven’t really stood the test of time. For instance, modern science tells us that drinking liquid mercury isn’t a good idea nor does it confer immortality, but that information comes a little late for Qin Shi Huang. Ha. 😛
Scott
January 16, 2021 at 6:42 amWhat about the fan leaf? Not the flower buds. Can the leaves be used for tea too?
Aaron von Frank
January 16, 2021 at 11:59 amHi Scott! Milk thistle leaves are edible as well. They’re best eaten young, cooked, and with spines removed. So it’s safe to assume you could also use the thistle leaves for tea, although we can’t attest to their flavor since we’ve never used them in tea. You’d probably want to use them in a mix with a more flavorful herb such as mint.
cortijoman
December 7, 2020 at 7:39 amIf you want to make thistle seeds a lot more palatable just toast them for a couple of minutes without oil in a pan. They go from being a slightly weird challenge for your teeth to a delicious snack. I bought a kilo of seeds online and next year I will be following your advice on how to grow them.
Aaron von Frank
December 7, 2020 at 10:58 amGood milk thistle tip, thank you! We’ll give this a try.
Donna Cave Ginn
May 17, 2021 at 2:07 pmI moved to Western NC where Milk Thistle grows wild. We love feeding the pollinators and the yellow finches with this herb. This year we are going to cultivate the seeds if the birds leave any. The leaves on these plants are not was wide as your pictures are they still able to be eaten? Also, how do I prepare the stems to eat? How and when do I harvest the milk? Could I just cut a stem, ( at what age) and dab the milk on precancer lesions? Or do I have to harvest differently? If you could tell me from the time it begins to grow in the spring to the time I may harvest milk would be appriciated!
Thank you!
Aaron von Frank
May 19, 2021 at 1:04 pmIt’s possible that what you’re seeing in the wild is bull thistle (quite common here in the Carolinas) or something similar, not milk thistle. Thistle leaves are best eaten young. Cut off the leaf spikes and use like spinach in cooked recipes. Milk thistle stems are best when very young as well, but harvesting them means no flowers and probably killing the plant. The sap/milk can be accessed at any stage as long as the plants are still green and growing. Once they set seed and begin to die, there’s not much sap to be found. I’m not qualified to recommend milk thistle as a skin cancer treatment and would advise consulting a medical professional about such things.