Milk Thistle Identification and Uses

Milk thistle is one of the easiest to identify foraging offerings in the fall. The plant is used in natural medicinal remedies, to brew as a tea, and as a recipe ingredient.

Like stinging nettles, you MUST wear gloves when harvesting any part of this plant – or suffer the consequences of having tiny and clear little thorns embedded into your fingers.

milk thistle flower
milk thistle flower

Milk thistle has been considered nothing more than an annoying weed by farmers, and is often brush hogged down during routine field maintenance.

If left unattended, milk thistle can take over a field thanks to the easy and rapid dispersal of its seeds by even a slight wind.

Even though milk thistle is indigenous to Asia, Europe, and North Africa, it has now been naturalized in the United States, Australia, and South America. naturalized in North and South America and Australia. Although many consider it an invasive weed, still.

While milk thistle grows abundantly in the wild nearly throughout the United States, it is possible to purchase seeds to cultivate this plant – or purchase it in supplement form at health food stores.

It is most often found in grocery stores in a tea format. All parts of the plant are edible, when properly prepared and harvested, and can be used in a wide variety of recipes to bolster their nutritional content and flavor.

This edible and healing weed gets its name from the Bible. The virgin Mary was sheltering herself from the elements and possible evil doers beneath the prickly leaves of the milk thistle plant while nursing the baby Jesus, according to some ancient stories.

A drop of Mary’s milk dropped onto one of the leaves, and caused the milky veins that are present in the plant to form.

This wild plant is first known to have been used in ancient Greece more than 2,000 years ago. The Greeks used milk thistle to treat snake bites and liver problems.

Milk thistle hails from the mountain regions of the Mediterranean. This attractive yet prickly fall foraging wild edible belongs to the same plant family as artichokes and daisies.

It was herbalists from Great Britain that significantly enhanced the use of milk thistle’s use by early medical care providers, especially for the treatment of kidney and spleen disorders.

It was Dioscorides, a Greek botanist and doctor who first prescribed milk thistle to treat hepatobiliary diseases. Nicholas Cuplepper, a 17th century English herbalist, used the wild plant to treat jaundice and remove obstructions in both the spleen and liver.

It was in both Europe and in the early days of America that milk thistle leaves had their spines removed so they could be eaten as a vegetable and tossed in salads.

Roots and stalks were also cleaned and used in the same types of common menu items. The cone flower portion of the plant was commonly used at the time as a food that was eaten in a similar manner as the artichoke is consumed today.

Native American tribes often used milk thistle to treat skin rashes, diseases, and boils.

Is Milk Thistle The Same As Milkweed?

Milkweed and milk thistle are not the same plant. Milkweed is a bright plant that produces large and colorful flowers that attract butterflies in great abundance.

Unlike milkweed that grows in the spring and blooms in the middle of summer, milk thistle grows in the summer and blooms just as the season is ending – in most climates.

However, milk thistle is quite popular with many pollinators such as bees and is a common addition to gardens to those looking to attract them. Just like milkweed, you can find milk thistle along roadsides and in pastures.

If you have any cattle or other livestock you may want to keep their exposure to this plant limited. Ingesting it in large quantities can make them sick. This is why you don’t see it at operational farms.

Is Milk Thistle The Same As Scotch Thistle?

Yes. Milk thistle or silybum marianum, is a fall foraging plant with many nicknames. This edible weed is also known as:

  • Scotch Thistle
  • Holy Thistle
  • Mary Thistle
  • Blessed Thistle
  • Saint Mary’s Thistle
  • Variegated Thistle
  • Marian Thistle
  • Carduus Marianus
  • Mediterranean Milk Thistle
milk thistle cone dying off
milk thistle cone dying off

How To Identify Milk Thistle

It is during the initial days of fall when milk thistle begins to fade. The purple cones that grow atop the tall and thin “branches” of this bush-style plant die off, leaving white fluffy where the thin purple flower petals had grown.

Each cone shaped flower on the milk thistle is capable of producing approximately 200 seeds. An entire plant can contain (and release) around 6,350 seeds. The flowers typically range in size from about 1 1/2 inches to nearly 6 inches long.

In North America, the flowers generally bloom from June to August, but in the southern hemisphere milk thistle flowers tend to bloom from December through February.

The white fluff are the seeds. They somewhat resemble the top of a dandelion that children love to blow like bubbles. The white heads that are present on the cone are known as pappus.

Broken stems and leaves will expose a milky sap from which many folks believe the plant got its name. The fruit portion of milk thistle is found in the pappus that falls away when the plant dries, and is not used to make an extract.

It is only the gray or black mottled and shiny portion of the fruit that are regularly referred to as seeds that are used to make milk thistle extract.

died out milk thistle
Milk thistle flower that has died out.

Milk thistle is a sturdy annual or biennial plant. It typically grows up to at least 3 feet tall. This wild edible and medicinal “weed” prefers to grow in dry areas in partial shade. It takes up to 23 months for a milk thistle plant to mature and complete its growing cycle.

Leaves on the milk thistle plant are lanceolate or oblong in shape. They are hairless and alternate up the stem of the plant.

Milky and white veins are visible on the leaves via a close inspection of them. The upper leaves on this wild edible ultimately clasp together at the stem.

milk thistle stem and leaves
Milk thistle stem.

This fall foraging all star has a branched stem filled with leaves that boast a prickly appearance and texture. Again, do not attempt to harvest milk thistle without wearing durable work gloves.

You can use a butter knife to scrape the prickly parts if needed.

When dealing with a particularly dry or spikey plant, I can even feel the tiny yet sharp thorns through my lined leather work gloves.

milk thistle leaves
Milk thistle leaves.


While I am not a doctor or any type of medical professional, I am going to share with you the traditional natural uses for milk thistle – some of which date back centuries. This information is for research and entertainment purposes only.

Before embarking on any type of natural remedy journey, always do your own research and consult with your physician first. Simply because a remedy ingredient is natural, does not mean it is safe to use for everyone.

What are The Edible Parts of Milk Thistle?

  • Leaves – after boiling
  • Young stalks
  • Flowers
  • Young thistle root

All parts of the plant can be eaten cooked, only some can be eaten raw. raw – The exception is the the need to boil the leaves to remove their prickles.

Cooked milk thistle leaves make a superb substitute for spinach. Cooked flower buds have a slightly sweet taste, and are delicious when brewed into a tea.

Stems from this fall foraging survival plant taste best when peeled and soaked in cold water to reduce their bitter taste, before being eaten either raw or cooked.

The stems taste better when eaten while the plant is still young. They can be used in place of lettuce in salads, as an asparagus substitute in recipes, and in place of rhubarb.

If you roast the seeds, they can be used as a coffee substitute – at least to replicate the flavor of the morning drink if not the caffeine intake.

How to Harvest Milk Thistle

As noted above, the leaves and spines of the milk thistle plant are filled with little prickly hairs that will act as tiny thorns if given the chance to get under your skin.

You will know that it is time to begin harvesting the flower cones begin to dry out and the purple heads on the cones turn to white.

The milk thistle plant should not be expected to mature at the same time. During your fall foraging, keep an eye on the plant just about daily during the final days of September and into the first week or so of October for signs of drying and pappus.

Steps to harvest it correctly:

  1. Use sturdy work gloves and cut the flower cone blossoms away from the stem.
  2. Put the flower heads into a sack to prevent the pappus from flying away in the wind. Even a slight wind is all it takes to broadcast the white flowery seeds. Sometimes, just the movement of your hands while popping off the cone or snipping it away can dislodge at least part of the pappus.
  3. Leave the flower heads inside of the bag, and hang in a cool dry place for about a week to allow them to dry thoroughly.
  4. After the cone heads have dried, remove them from the sack, and separate out the seeds after giving it several solid shakes and pressing down on the flower cones to separate them thoroughly.
  5. Pour the dried seeds in to a storage container with an airtight lid and pick out any chaff that did not blow away during the harvesting process. The milk thistle seeds should be stored in a cool dry place until ready to use.

Milk Thistle Precautions and Warnings

Because milk thistle is related to ragweed, folks with seasonal allergies to this wild plant should avoid consuming it as either a fall foraging for edible or medicinal purposes. If you are allergic to chrysanthemums, daisies, or marigolds, it may be best to avoid using milk thistle as well.

Pregnant and nursing women are also cautioned against the consumption or use of milk thistle because testing on this population just has not been extensive and too many potential health unknowns exist.

Women with ovarian, uterine, or breast cancer, as well as those suffering from hormone sensitive conditions like uterine fibroids or endometriosis, should not consume or use milk thistle unless doing so under the supervision of their doctor. The plant’s extract might cause estrogenic effects.

Side effects that may indicate an allergic reaction to milk thistle include:

  • Diarrhea
  • Upset stomach or bloating
  • Nausea
  • Skin rash – itching
  • Gas
  • Loss of appetite

Avoid using milk thistle if taking metronidazole, Simeprevir, and drugs to treat hepatitis C.

Milk Thistle Dosage

Typically, milk thistle dosing guidelines are recommended to be no more than 140 mg consumed orally three times per day for adults.

Some supplement bottles containing milk thistle in capsule or pill format suggest that use of this wild edible may be safe at a level of 420 mg daily for up to 41 months.

Preserving Milk Thistle

The wild plant can be dehydrated in the sun or a dehydrator machine to speed up the drying process, if necessary. I would recommend using the herb or nut setting on a standard home dehydrator, allowing it to dry for about 5 hours.

When dehydrating the flower cone head, plant pieces should be extremely brittle to the touch when the drying process is complete.

Dehydrating the harvested roots from the plant may take up to 12 hours in a standard home dehydrator.

Stems should also be dehydrated on the same setting, and will likely take up to at least 8 hours to dry, depending upon their girth.

Leaves will not usually take more than 3 – 4 hours to dry completely in a typical home dehydrator on the “nut and herb” setting.

When using the potent power of the sun to dehydrate milk thistle, the amount of time the process will take will depend upon both the temperature and humidity level.

Expect solar dehydrating to cut the standard air drying or sack drying time approximately in half. Always bring the milk thistle plant pieces being dehydrated by the sun inside at night to prevent dampness from infusing into them, and cause drying delays.

To air dry milk thistle, simply tie the stems to a piece of twine or rope and hang as you would herbs. There is no need to remove the roots or leaves from the stem to air dry.

The pappus on the heads will be dispersed or fall out during the air drying process, so they must be removed and placed in a sack as noted above.

Store dehydrated portions of the milk thistle plant in an airtight container like a Mason jar, or seal them with a vacuum sealer machine. Storing the dried milk thistle plant in a cool and dry place is highly recommended.

Learning how to identify milk thistle or how to grow it in your prepper apothecary, could help increase your chances of survival during a long-term disaster. The skills we have honed are just as vital to our survival as the tools and gear we stockpile.

Even if you have planned extensively to bug in, the possibility that you could be forced to bug out instead and rely perhaps solely upon your survival foraging knowledge, does exist.

Preppers who do not have to bug out still may find themselves in a position where food and medicine stockpiles need replenished.

As we all know, grocery store shelves will be emptied in mere hours – and pharmacies will be looted – so learn as much as you can right now about how to identify and use milk thistle and other valuable plants growing in your region. This survival knowledge just might save your life – or the life of someone you love.

Frequently Asked Questions

Milk thistle is probably a new ingredient to some of the readers so here’s a head start with some of the more common questions surrounding the harvesting and consumption of this wild edible.

What part of the milk thistle is edible?

You can consume any part of the plant itself. Keep in mind though that you do have to properly prepare the plant for eating. This includes removing the prickly hairs that can get under your skin.

Where can I harvest milk thistle?

This plant can be found at the side of roadways and highways all over North America. Farmers will find it growing in their pastures and have to take it out before it takes over the entire area.

When is the best time to harvest milk thistle?

Once the last flower is ripe the plant will start the decline into death. Late September through to October is a great time to harvest the seeds. The leaves can be eaten throughout the year.

Definitely Forage This Wild Edible

As with many mistaken weeds, a lot of which are invasive or naturalized, milk thistle is a hidden edible gem. It does take some effort to prepare the plant and there will be some pain involved but the result is worth it.

Exercise caution when harvesting and don’t worry about taking too much as this plant spreads like wildfire. Check out some of our other wild edible articles and see the world living among us for what it is.

milk thistle Pinterest image

3 thoughts on “Milk Thistle Identification and Uses”

  1. I am chuckling. While I will defer to experts about much of the Bible, that yarn about the Virgin Mary is DEFINITELY not in the Bible.

  2. The image titled “This is what milk thistle cone flowers look like before they bloom” is not Milk Thistle. It’s cutleaf teasel: Dipsacus laciniatus (Dipsacales: Dipsacaceae)

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