Often misunderstood and disregarded, the thistle is a surprisingly versatile plant that has been used for centuries both as food and medicine.
Here’s how to forage this abundant plant, learn how to prepare its different parts, and discover the potential therapeutic uses it may hold.
1. Thistle Roots
Thistle roots are edible! They’ve been used for food and medicine for centuries. Here’s how to forage them:
Identifying Edible Thistles
- Bull Thistle (Cirsium vulgare): The young roots can be peeled, cooked, and eaten, offering a slightly sweet and nutty flavor similar to parsnips.
- Canada Thistle (Cirsium arvense): The roots are also edible when young and tender, often roasted or boiled and having a similar taste to Jerusalem artichokes.
- Milk thistle (Silybum marianum): Roots are edible and can be prepared similarly to other root vegetables. They may have a slightly bitter taste.
When & Where to Forage
- Time: Best harvested in fall or early spring when the plant’s energy is concentrated in the root.
- Location: Look for thistles in meadows, fields, and disturbed areas.
Harvesting Thistle Roots
- Choose young plants: Younger plants have more tender, less fibrous roots.
- Dig carefully: Use a shovel or trowel to dig around the base of the plant, being careful not to damage the root.
- Loosen the soil: Gently loosen the soil around the root and pull it up from the ground.
- Clean and prepare: Wash the root thoroughly to remove dirt and debris. Peel the outer skin before cooking.
Preparing Thistle Roots
- Cooking: Thistle roots can be roasted, boiled, or sauteed. They have a slightly sweet, earthy flavor similar to Jerusalem artichoke.
2. Thistle Leaves
Thistle leaves are edible, but they require careful preparation due to their spiny nature. Here’s how to forage and prepare them:
Identifying Edible Thistles (for Leaves)
- Bull Thistle (Cirsium vulgare): Young leaves are best. Mature leaves are too tough and prickly.
- Canada Thistle (Cirsium arvense): Choose young, tender leaves from the center of the rosette before the plant flowers. These will be less prickly and bitter than older leaves.
- Milk thistle (Silybum marianum): The young, tender leaves of milk thistle can be eaten raw in salads or cooked like spinach. However, as the plant matures, the leaves become tough and spiny
When & Where to Forage
- Time: Spring is the ideal time to harvest young, tender thistle leaves.
- Location: Look for thistles in meadows, fields, and disturbed areas.
Harvesting Thistle Leaves
- Wear gloves: Protect your hands from the prickly spines.
- Select young leaves: Choose small, tender leaves from the center of the rosette.
- Cut carefully: Use a knife or scissors to carefully cut the leaves at the base, avoiding the spines.
Preparing Thistle Leaves
- Remove spines: Carefully remove the spines from the leaves using a knife or peeler.
- Soak or blanch: Soak the leaves in salt water for a few hours or blanch them in boiling water to soften them and reduce bitterness.
- Cook: Thistle leaves can be cooked like spinach or other greens. They can be added to soups, stews, or stir-fries.
- Midribs: The midribs of large thistle leaves can be peeled and cooked like celery.
3. Thistle Stalks
Thistle stalks are edible and can be a surprisingly delicious and nutritious wild food! Here’s how to forage and prepare them:
Identifying Edible Thistles (for Stalks)
- Bull Thistle (Cirsium vulgare): Young stalks are best before the flower buds form.
- Canada Thistle (Cirsium arvense): Harvest stalks before the plant flowers, ideally when they are still short and haven’t developed a tough, woody texture.
- Milk thistle (Silybum marianum): The stalks are edible, but they can be quite fibrous. They are best harvested when young and tender and can be peeled and cooked like asparagus.
When & Where to Forage
- Time: Spring and early summer are the best times to harvest young, tender thistle stalks.
- Location: Look for thistles in meadows, fields, and disturbed areas.
Harvesting Thistle Stalks
- Wear gloves: Protect your hands from the prickly spines.
- Select young stalks: Choose stalks that are still tender and haven’t developed flower buds.
- Cut carefully: Use a knife or scissors to carefully cut the stalk near the base, avoiding the spines.
Preparing Thistle Stalks
- Remove spines: Carefully peel away the outer layer of the stalk using a knife or vegetable peeler, removing all spines.
- Peel fibrous layer: Depending on the thistle variety and the stalk’s age, you might need to peel away an inner fibrous layer as well.
- Soak or blanch: Soaking the peeled stalks in salt water or blanching them briefly can help reduce bitterness.
- Cook or eat raw: Thistle stalks can be eaten raw, added to salads, or cooked like asparagus or celery.
4. Thistle Blossoms
Thistle blossoms are edible, and they can be a unique and flavorful addition to your foraged meals. Here’s how to forage and prepare them:
Identifying Edible Thistles (for Blossoms)
- Bull Thistle (Cirsium vulgare): The young flower buds are the most desirable part, as they are less prickly and have a more delicate flavor.
- Canada Thistle (Cirsium arvense): Young, unopened buds are best. They have a slightly sweet, artichoke-like flavor.
- Milk thistle (Silybum marianum): The flower buds are edible and have a slightly sweet, artichoke-like flavor.
When & Where to Forage
- Time: Late spring and early summer are the best times to harvest thistle blossoms, as this is when they are in their prime.
- Location: Look for thistles in meadows, fields, and disturbed areas.
Harvesting Thistle Blossoms
- Wear gloves: Protect your hands from the prickly spines.
- Select young buds: Choose flower buds that are still tight and haven’t opened yet.
- Cut carefully: Use a knife or scissors to carefully cut the flower bud at the base, leaving a short stem.
Preparing Thistle Blossoms
- Remove spines: Carefully remove the outer spiny bracts from the flower bud using a knife or your fingers. You may also want to remove the green base of the bud.
- Soak: Soaking the buds in cold water for a few minutes can help remove any remaining bitterness.
- Cook or eat raw: Thistle blossoms can be eaten raw, added to salads, or cooked. They can be steamed, sautéed, or even battered and fried.
Thistle’s Medicinal Uses
Thistle, particularly milk thistle, has been used for centuries in traditional medicine for its potential liver-protective properties.(ref) Some studies suggest it may be beneficial for people with liver conditions like non-alcoholic fatty liver disease and cirrhosis.(ref)
Canada thistle also has active compounds that promote antioxidant and anti-inflammatory effects, which may help protect liver cells from damage caused by toxins, alcohol, and certain medications.(ref)
Preliminary research also suggests that bull thistle may have potential anti-inflammatory effects, which could be beneficial for individuals with arthritic conditions.(ref)
Also, be careful in foraging other thistle types, such as musk thistle (Carduus nutans), because some states consider them as noxious weeds.(ref)
While scientific research on the effectiveness of thistle types for health is still ongoing, it’s advisable to consult with a healthcare professional before using thistle for medicinal purposes, especially if you have any underlying health conditions or are taking medications.
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Nancy has been a plant person from an early age. That interest blossomed into a bachelor’s in biology from Elmira College and a master’s degree in horticulture and communications from the University of Kentucky. Nancy worked in plant taxonomy at the University of Florida and the L. H. Bailey Hortorium at Cornell University, and wrote and edited gardening books at Rodale Press in Emmaus, PA. Her interests are plant identification, gardening, hiking, and reading.