Wild Lettuce Soup (And Other Soothing Bedtime Stories)

Do you know where the wild lettuce grows? Ask a bunny. In Beatrix Potter’s eponymous tale, the Flopsy Bunnies eat too many lettuces and fall asleep in an ill-advised spot, where Mr. MacGregor finds them. These were “overgrown lettuces, which had shot into flower” to be thrown on a rubbish heap; mature lettuces produce a lot of milky sap (hence their genus name Lactuca), and this sap has been used in folk medicines for millennia to calm and to soothe (dried, it is known as lettuce opium). And then there are Edward Lear’s Old Guinea Pigs, who caution: “Have a care that you eat your Lettuces, should you find any, not greedily but calmly.” The little guinea pigs did not follow their advice.

These favorite childhood stories and an abundance of wild lettuce locally (in flower, as I write) are how my recipe for a chilled wild lettuce soup was born. The emerald soup is restorative, and can be made with tame lettuces, too, or other leafy greens.

Photography by Marie Viljoen.

Lettuces may in fact be soporific; exploratory studies are beginning to (tentatively) substantiate traditional medicine’s deployment of lettuce powders and oils as a sleep aid and analgesic. In a culinary context, you’d have to eat as many as those greedy rabbits did to feel any effects. But the antioxidants and high fiber in lettuce, plus the drowsy-bunny appeal, are reason enough to eat more wild lettuce. It is an under-appreciated vegetable whose versatile nature should encourage culinary attention.

Wild lettuces as a group are not too hard to identify. Beginners might mistake them for dandelions, sow thistle (Sonchus oleraceus), or thistle species—not a serious error, since all are edible. It’s helpful to know that some lettuce species look very similar and are hard to tell apart until they bloom. This is also not serious, since there is no toxic species, but it will vex your inner plant geek.

Where I live, the two most common lookalike wild lettuces are Lactuca canadensis  and L. biennis (also known as tall blue lettuce). The stalks of both may be either a deep maroon or green. The leaves of both are highly variable. Both are tall, their hollow stems stretching up to human height.

L. biennis has very faintly hairy stems, while L. canadensis has fine hairs only on the leaves’ midribs. A useful distinction is that L. canadensis bleeds a slightly brown latex when cut. And a final “c” distinction is to remember that “canadensis clasps,” because its leaves clasp the stem.

Wild lettuces have potential to be sown and grown as bona fide vegetables. While we have bred the stems out of domesticated lettuce, consider celtuce, which is all stem (and challenging to cultivate). A tender wild lettuce stem is a true delicacy, and the plant is easier to grow. Harvest lettuce seeds this late summer and fall and offer them a spot in your vegetable plot. L. biennis will prefer some shade if you have it to spare.

Then there is prickly lettuce, Lactuca serriola. It is good to eat only when it is very young in spring, before the prickles have hardened into armor.

Depending on the stage of harvest, there are two main parts to eat in any wild lettuce: the stem in spring, while it is still tender, and the leaves, even if the stem has become mature and tough.

But to the soup: The hardest part about this soup is bringing a pot of water to the boil. While I might ordinarily steam most leafy greens, blanching the wild lettuce leaves removes much of their summer bitterness. I like bitter flavors, but these need some mellowing. The leaves are then drained and squeezed dry and added to a blender with a cooked base of scallion greens and rhubarb stalk (or lemon or sorrel, if those or unavailable). This is all puréed until lusciously smooth. Buttermilk is added. And this tonic-soup is ready.

I make a large batch to keep in a jar in the fridge for existential or actual emergencies, known to strike at midnight. Or 11AM.

Wild Lettuce Soup

Serves 2 as a meal, or 4 as an appetizer

Refreshingly good on a hot day, this fortifying, bright soup will make you lick the bowl and ask for more. The creaminess of tart buttermilk offsets the defining edge of wild lettuce, with a supporting splash of bright acid from sour rhubarb. Instead of rhubarb, you can add a tablespoonful of fresh lemon juice to the soup in the blender, or a handful of raw sorrel leaves (or wood sorrel). No wild lettuce? I have made this soup with Romaine and with spinach, too (they should also be blanched, to soften them).

• 8 oz tender wild lettuce leaves picked from the stems and washed
• 2 Tablespoons butter
• 1 packed cup finely chopped scallion or green onion leaves
• 1 stalk rhubarb, finely sliced (about 4 oz)
• 2 cups of vegetable or chicken broth
• ¼ teaspoon salt or to taste
• 1 cup buttermilk

Bring a large pot of water to a boil. Add the wild lettuce leaves and cook them for 2 to 3 minutes. They should still be bright green but bite-tender at their thickest part (the midrib).

Drain them and refresh at once in cold water. Squeeze the leaves dry, chop them, and reserve.

In the pot over medium-low heat cook the scallion greens and rhubarb in the butter until the rhubarb is soft, about 5 minutes. Add 2 cups of broth, stir, and bring to a simmer. Turn off the heat. When the mixture has cooled a little, transfer it to a blender. Add the chopped, blanched lettuce greens and purée until very smooth. Taste. Add the salt, if needed (some prepared broths or concentrates are already salty). Pour the soup into a jar or bowl and transfer to the fridge to chill.

To serve, pour into bowls and drizzle a ¼ cup of buttermilk over each. Dip in your spoons, and swirl. Then make like the bunnies, and take a nap.