Prickly Lettuce: A Wild Green I Use for Korean Wraps and Geotjeori Kimchi

Young prickly lettuce leaves are most tender before the tall flower stalk develops.

By the end of July, prickly lettuce looks very different from the tender green I gathered throughout spring.

Most of the plants around me have now grown tall. Small yellow flowers are beginning to open, and some plants are already moving toward seed production.

Once a wild green reaches this stage, I usually consider its best harvesting season to be over. The mature leaves are tougher, more prickly, and much more bitter.

But wild plants never follow one perfect schedule.

They do not all emerge on the same day, grow at the same speed, flower together, and disappear together. Even in midsummer, I sometimes find a younger plant or tender new growth close to the ground.

That is why I look at the actual condition of each plant rather than relying only on the calendar.

Throughout spring, prickly lettuce was not merely a weed I noticed while walking. It became one of the fresh seasonal vegetables I regularly brought to my table.

What Is Prickly Lettuce?

• English name: Prickly Lettuce
• Korean name: Gasi-sangchu (가시상추)
• Scientific name: Lactuca serriola
• Family: Asteraceae
• Life cycle: Annual or biennial
• Status in Washington: Introduced and widely naturalized, but not listed as a Washington State noxious weed

Prickly lettuce is closely related to cultivated garden lettuce, Lactuca sativa. Both belong to the genus Lactuca.

It commonly grows in fields, gardens, vacant lots, disturbed ground, and along roadsides. Its accepted native range extends primarily from Europe through parts of western Asia and northern Africa, but it is now naturalized across much of North America. 

A Wild Green I Gathered Throughout Spring

Sometimes I seasoned the leaves like geotjeori kimchi, a Korean-style fresh kimchi salad that is lightly seasoned and usually eaten right away rather than fermented for a long time. I occasionally mixed prickly lettuce with dandelion greens instead of preparing each wild green separately.

At other times, I kept the leaves completely fresh. I washed them carefully and dipped them into ssamjang just as I would eat lettuce, cucumber, or another raw vegetable.

I also used the leaves as Korean-style wraps. I wrapped them around grilled meat, or placed a very small amount of rice inside a leaf with a little ssamjang.

For me, prickly lettuce was not an herbal remedy. It was a fresh, pleasantly bitter spring vegetable that grew around me.

My Homemade Ssamjang

I make a simple ssamjang-style dipping sauce using:

• 1 part doenjang
• 1 part gochujang
• 1 part minced garlic
• 1 part sesame oil
• Ground sesame seeds to taste
• Finely chopped fresh pepper to taste

This is my personal homemade version rather than a fixed recipe. I adjust the ingredients depending on the saltiness of the doenjang and gochujang and how spicy I want the sauce to be.

Sometimes I dip prickly lettuce, cucumber, and other vegetables directly into this sauce.

When eating grilled meat, I place the meat and a small amount of ssamjang inside a tender leaf and fold it into one bite.

The slight bitterness of the wild leaf works especially well with rich grilled meat and savory ssamjang.

Why I Also Use the Leaves as Rice Wraps

I am especially careful about sharp rises in my blood sugar after eating rice.

Because of that, I try to eat plenty of vegetables and protein while keeping my rice portion quite small. Even when I eat only a little rice, I often place each bite inside a large leafy vegetable.

During spring, young prickly lettuce became one of the leaves I used for this purpose.

Instead of eating a meal centered on a large bowl of rice, I could enjoy a small amount of rice together with plenty of leafy greens, protein, and a little ssamjang.

Making one small wrap at a time also helped me slow down and enjoy my meal.

I am not saying that prickly lettuce itself treats diabetes or guarantees that blood sugar will not rise. The point is the way I build my entire meal: more leafy vegetables, enough protein, and a much smaller serving of rice.

The American Diabetes Association’s Diabetes Plate offers a similar general structure: half the plate is filled with non-starchy vegetables, one quarter with lean protein, and one quarter with quality carbohydrates. 

This is my personal way of eating and is not medical advice. Individual nutritional needs and blood glucose responses can be different.

How I Recognize Prickly Lettuce

The most useful identification feature is found underneath the leaf.

Turn the leaf over and examine its center vein. A row of small but distinct prickles runs along the underside of the midrib.

That feature explains the Korean name gasi-sangchu:

• Gasi means prickly or thorny.
• Sangchu means lettuce.

Other characteristics include:

• Lobed or toothed leaves
• Leaves that partially clasp the stem
• Small prickles along the leaf margins
• Milky white sap when a leaf or stem is broken
• Small, pale yellow flower heads
• A tall, branching flower stalk as the plant matures

Prickly lettuce can resemble sowthistles and other members of the daisy family.

Spiny sowthistle may have sharply toothed leaf margins, but it does not have the same characteristic row of prickles along the underside of the center vein.

Never identify a wild edible plant using only one feature.

A row of prickles along the underside of the center vein is one of
prickly lettuce’s most useful identification features.

Prickly Lettuce and Dandelion Geotjeori Kimchi

One of my favorite ways to prepare these leaves was as fresh geotjeori with dandelion greens.

People who gather Korean wild greens do not always prepare every species separately. Depending on the plants and the preparation they require, several correctly identified greens may be combined to create different flavors and textures.

Of course, a plant that must be cooked should never be casually added to a raw salad. Every species must first be identified and prepared according to its own requirements.

Both prickly lettuce and dandelion can be bitter.

I grew up in Korea hearing people say that bitter foods were good for the body, so a moderate amount of bitterness does not bother me.

Still, bitterness alone is not proof that a plant is medicinal or especially healthy. To me, it is simply part of the flavor and character of wild greens.

Want to See How I Make Prickly Lettuce Geotjeori?

In this video, I use young prickly lettuce leaves to make geotjeori, a fresh Korean kimchi salad that is seasoned and enjoyed without long fermentation.

🎥 Watch how I make Prickly Lettuce Geotjeori here

Fresh Was Better Than Blanched for Me

I also tried blanching prickly lettuce and seasoning it as cooked namul.

I expected blanching to reduce its bitterness, but the leaves I prepared actually tasted even more bitter afterward.

That was my personal cooking experience. The result may vary depending on the plant’s age, growing conditions, and preparation method.

For me, the tender young leaves were much more enjoyable when eaten fresh—as geotjeori, dipped into ssamjang, or wrapped around meat and a small amount of rice.

Is Late July Too Late to Gather It?

By late July, most prickly lettuce plants around me have already developed tall, branching flower stalks.

Some have unopened yellow buds, some are flowering, and others are beginning to form seeds.

Once a plant reaches this stage, I do not gather its old, tough leaves for food. Its best season as a tender wild green has mostly passed.

However, not every plant grows on the same schedule. I may still find a younger plant or tender new leaves growing close to the ground.

I inspect every plant individually.

If the leaves are still young and soft, I may gather a few from a clean location. If they are tough, extremely bitter, or heavily armed with prickles, I leave them alone.

By late July, many prickly lettuce plants have bolted
and begun producing yellow flowers and seeds.

Is Prickly Lettuce Invasive in Washington?

Prickly lettuce is not native to Washington State. However, an introduced plant is not automatically a legally designated noxious weed.

Prickly lettuce is not currently listed as a Washington State noxious weed, and statewide control is not required under Washington’s noxious-weed law.

In 2023, the Washington State Noxious Weed Control Board considered adding Lactuca serriola to the state list.

The board decided not to add it because the plant was already naturalized throughout Washington and western North America and was considered relatively easy to control. 

Plant classifications and harvesting rules vary by country, state, county, and type of land. Because these plants grow around my home in the Pacific Northwest, I use Washington State information when describing their local status.

Even though prickly lettuce is not a Washington-listed noxious weed, I do not intentionally introduce its seeds into natural areas.

“Not listed” does not mean that a non-native plant should be spread wherever we want.

What Is the White Milky Sap?

When a prickly lettuce leaf or stem is broken, it releases a white, milky latex. This is a common characteristic of plants in the Lactuca genus.

Wild lettuce species contain bitter plant compounds, including sesquiterpene lactones such as lactucin and lactucopicrin.

Laboratory and animal studies have investigated possible sedative, pain-relieving, antispasmodic, and antioxidant activity.

However, those studies do not prove that eating a few prickly lettuce leaves will treat insomnia, improve eyesight, lower blood pressure, relieve pain, reduce inflammation, or act as a diuretic.

Research involving concentrated extracts, isolated compounds, or animal models is not equivalent to eating young leaves as part of a meal.

The term lactucarium traditionally refers to collected and dried or concentrated lettuce latex, particularly from certain wild lettuce species.

It should not be used as though it simply means the small amount of fresh white sap visible when a prickly lettuce leaf is picked.

I do not collect, concentrate, or consume the latex.

I enjoy correctly identified young prickly lettuce as a seasonal wild food—not as a sleeping remedy, pain reliever, or medicine.

A cut prickly lettuce stem releases white latex,
but the sap should never be used as a taste test or concentrated as a home remedy.

Foraging and Food Safety

⚠️ Foraging Safety: Never eat a wild plant unless you are 100% certain of its identification.

Prickly lettuce can be confused with sowthistles and several other similar-looking plants. Confirm multiple characteristics and never rely only on an online photograph.

Avoid harvesting near roads, heavy traffic, sprayed fields or landscapes, polluted areas, pet waste, or contaminated soil and water.

Harvest only from clean environments, and make sure collecting is permitted on the land.

Choose young, tender leaves and wash them thoroughly. Try only a small amount the first time because individual sensitivities and allergies can vary.

The presence of white sap does not confirm that a plant is edible, and plant sap should never be tasted as an identification test.

This post shares my personal food experience and is not medical advice.

A Familiar Korean Way of Eating in the Pacific Northwest

Prickly lettuce may look like an ordinary weed to many people.

For me, it is one more plant that connects the landscape around my Washington home with the Korean foods and traditions I grew up with.

Sometimes I dip its tender leaves into ssamjang.

Sometimes I wrap them around grilled meat.

Sometimes I combine them with dandelion greens to make fresh geotjeori.

And sometimes I place just a small amount of rice inside a large leaf so that vegetables—not rice—remain the center of my meal.

By late July, most prickly lettuce plants have already reached the flowering and seed-producing stage. But when I slow down and look closely, I may still discover a younger plant growing nearby.

That is one of the lessons wild plants continually teach me: the season does not begin or end for every plant on exactly the same day.

Want to See Prickly Lettuce in Video?

The prickles beneath the leaf and the plant’s tall summer growth are much easier to recognize in video.

🎥 Watch my Prickly Lettuce Short here

You May Also Enjoy

If you enjoy Korean-style wild greens and seasonal foraging, you may also enjoy:

🌿 Related article: Broadleaf & Narrowleaf Plantain: The Wild Vegetable Growing Right Beneath Our Feet

🌿 Read next: Bull Thistle – How I Recognize This Beautiful but Extremely Sharp Plant

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Some wild plants are mild.
Some are bitter.
And some connect the landscape where we live with the food traditions we grew up with.

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