Wild Lettuce: A Delicious Foraged Vegetable that Makes an Outstanding Summer Soup

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.