Everything You Have Always Wanted to Know About Dock
Docks were popular wild edibles during the Great Depression due to their tart, lemony flavor, their widespread abundance, and the fact that they were free for the taking. Today, most people have forgotten about this common and tasty edible weed.
Docks are perennial plants growing from taproots, and they are most often found in neglected, disturbed ground like open fields and along roadsides. While docks may be happiest and tastiest when they grow with plenty of moisture, the taproot indicates they are drought-tolerant plants. Docks grow as basal rosettes of foliage in early spring; they are often one of the first greens to emerge. By late spring or early summer, dock produces tall flower stalks that bear copious amounts of seed, which are also edible. The seed, however, can be labor-intensive to process and reports on its palatability are highly varied.
The foliage of mature dock plants may be from one to three feet tall, depending on growing conditions, but in early spring, when it's at its most delicious, the smaller plants may be hard to spot. Look for the tall, dark brown, branched flower stalks that produced the prior year's seed crop. These often remain standing over winter and new growth will emerge from the base of the stalk.
Which Docks Are Edible?
There are many edible docks, but curly dock and broad-leaved dock are the most common in the USA and Europe. Other edible docks include R. occidentalis (western dock), R. longifolius (yard dock), and R. stenphyllus (field dock). R. hymenosepalus (wild rhubarb) is common in the desert in the American Southwest. It is larger and more succulent than many other docks. It has been a traditional food and dye source for several Indigenous tribes.
Patience dock (R. patientia) was once cultivated as a vegetable in both the USA and Europe and is still grown as such by a small number of gardeners. Patience dock may be found as a feral plant. It's larger, more tender, and perhaps more delicious than any other dock plant. Seeds can be found for sale online.
One of the best identification features for docks is the thin sheath that covers the nodes where leaves emerge. This is called the ocrea, and it turns brown as the plant ages. The condition of the ocrea may be a good indicator of how tender and tasty that dock plant is. A second excellent identification feature is the mucilaginous quality of the stems. Know that only young dock leaves are covered with mucilage.
The sour flavor of dock comes from oxalic acid, which, when consumed in large quantities, may cause kidney stones. The same compound is found in spinach. If eating spinach is against physician’s orders or for those who are prone to kidney stones, don’t eat dock. Now, for those who are generally healthy and don’t eat large quantities of dock on a regular basis, it should be fine. For those who are nervous about this, err on the side of caution.
Curly dock may also be called yellow dock, sour dock, or narrowleaf dock, depending on where they are purchased. Common names are tricky for that very reason; they change from place to place. For those who need to know precisely and with absolute certainty which plant they're dealing with, use the botanical Latin name.
How and When to Harvest
Both curly and broad-leaved dock are edible at several stages. The most tender leaves and the best lemon flavored ones come from young docks with flower stalks that have yet to develop. Pick two to six youngest of the leaves at the center of each clump. They may not even have fully unfurled, and they will be very mucilaginous.
From early to mid-spring, young leaves are tasty raw or cooked. If using raw leaves, avoid excessive mucilage by removing the leaf stem (petiole) and using only the actual leaves in salads.
The midribs of large dock leaves can be tough and fibrous, while the leaf blade remains tender. If a plant with tasty foliage but tough midribs is found, remove the midrib from the leaf before cooking. Additionally, larger petioles may be tough but pleasantly sour. Consider chopping the petioles into small pieces, and cooking them as a substitute for rhubarb or Japanese knotweed.
In the Kitchen
Like so many greens, docks reduce in volume when cooked, by about 20 to 25 percent of their original volume.
Boil or saute dock greens to make the most of their flavor. They are excellent in stir-fries, soups, stews, egg dishes, and even cream cheese. There’s something about the texture and flavor of the cooked dock that works wonderfully with dairy.
Because dock has a relatively short harvest season, like so many wild greens, harvest as much as you can when it’s at its peak, then blanch and freeze for later use. Dock is considered an invasive weed in fifteen states, so foraging probably won’t make a dent in the local population. Try vacuum sealing and freezing a bag of dock for winter months when the promise of spring greens seems like a cruel culinary tease.
Weed of the Month: Curly Dock
I have nothing good to say about curly dock. Many entries in the Weed of the Month column might be appreciated as wildflowers—blue violet and Queen Anne’s lace, for example—or harvested as greens, like purslane or lambsquarters. But Rumex crispus is nothing but a burly, exploitative thug, just waiting to take over the flower bed and vegetable garden.
In the lawn, its basal rosette crowds out the grass. Mow it and it grows back fast, poking well above the surrounding turf. Even if the entire plant top is removed, this tough perennial can regenerate from its strong, deep taproot.
I once encountered a couple of mature curly dock plants that had established themselves in the rich loam of an old garden I was renovating. I needed a deep bed for my asparagus patch and took my spade to the weeds, digging down around them and tugging hard at the crown. No luck. I dug some more and cleared as much soil as I could around the forked taproots…tugged some more. Still no go. It took me hours, and when I finally prized the entire, entwined root systems from the yard-deep hole I’d had to excavate, I dragged them over and nailed them to the side of the shed like an old-school farmer would the pelt of a fox to warn off other barnyard varmints. Not that the other curly dock in my garden paid any mind, but it gave me some satisfaction.
Left alone, curly dock will grow four feet or taller and produce thousands of seeds, which can spread by wind and water and by catching rides on passing animals. If they don’t find immediate purchase—and they can thrive almost anywhere—the seeds can remain viable for 50 years or more waiting for good conditions. A few birds and insects feed on the leaves and seeds, but most mammals leave it to proliferate.
A member of the buckwheat family (Polygonaceae), curly dock came over from Europe with early settlers, probably in the coats of livestock and mixed with crop seed, and quickly made itself at home throughout North America’s fields and lots, along roadsides, and anywhere else the soil has been disturbed. Various parts of the plant are edible in small amounts with careful preparation, and the roots are used in some homeopathic remedies. Nevertheless, curly dock is considered toxic to livestock and widely listed as a noxious weed.
Sometimes called yellow dock, this plant can be recognized by its long, wavy-edged dark green leaves—sometimes tinged with red—large at the base of the plant and becoming smaller toward the top of the single, jointed stem. In late spring, a slightly branched flower stalk forms, and over the summer, hundreds of tiny light yellow-green flowers bloom in whorls. Each flower produces one seed, and as it matures, its surrounding winglike husk of sepals turns brown and papery. Later in the season, the leaves die back, leaving a distinctive rust-brown seed stalk.
Persistent mowing will eventually eliminate curly dock in the lawn. To control it in the garden, dig out—don’t pull—individual plants as soon as they are discovered; once established, they’re hard to extricate. This is easier to accomplish when the soil is moist. Keep an eye out for sprouts from remaining roots missed the first time around.
The Weed of the Month series explores the ecology and history of the common wild plants that most gardeners consider weeds.
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Joni Blackburn is a former copy editor at Brooklyn Botanic Garden. She writes and gardens in the Catskills.
Curly dock: edible invasive weed
Curly dock (Rumex crispus) is one of the many wild edible invasive plants we have in North America.
It’s toxic to horses, cattle, and sheep, and the seeds are poisonous to poultry, so it’s not something you want in your pasture. And if you do have it, it’s not easy to get rid of.
It doesn’t really take over like some other “nuisance” plants (ground ivy for instance) but it can be somewhat difficult to deal with in your garden.
Any effort to remove this tenacious weed is usually rewarded with more of it. Each chunk of root left behind will sprout a new plant, so pulling and digging just makes more work if you don’t get all of it the first time.
But it is edible, so you could just treat it as a crop when it’s young and tender enough to eat.
Curly dock (Rumex crispus) leaves
Curly dock gets its name from its leaves — they have “curly” or wavy edges.
They initially grow from a basal rosette. When the plant gets older and sends up a flower stalk, leaves will also grow alternately off of the stalk.
They’re hairless and mostly green but tend to get tinged with rusty red as they get older. They can grow up to ten or 12 inches long and 2.5 inches wide.
The leaves are joined to the rosette by petioles (leaf stems) which are encased at the leaf node by a thin sheath called an ocrea.
They start out rolled up length-wise, appearing more as a stem than a leaf.
At this point, they’re really mucilaginous, which makes them slimy. Just after they unroll, the leaves will start to dry out, but the stems and sheaths will still be slimy.
As they get older, the stems will also dry up and the sheaths will get more papery.
The nickname “Yellow dock” is derived from the color of its large, thick taproot, which can grow as long as four feet.
Like a lot of other invasive weeds, curly dock will grow in almost any disturbed area, so it’s common in pastures and fields, as well as roadsides, construction sites, etc.
It really thrives in more damp soil near creeks, ponds, springs, and other water ways.
Invasive as it is, though, curly dock doesn’t seem to be a problem in more pristine, undisturbed areas.
Curly dock is in the Polygonaceae family (the buckwheat family), which is the same family that rhubarb belongs to. It’s also closely related to garden sorrel (Rumex acetosa), but it’s not related to burdock.
Like rhubarb and sorrel, dock is sour. Oxalic acid is what makes it sour.
A little bit of oxalic acid goes a long way, though, and as dock gets older, the sour turns more to bitter and gets potentially dangerous.
But dock leaves, even the younger ones sometimes, are not always tasty enough to eat raw. I believe it depends to a large degree on what type of soil they grow in.
If they’re mild enough (sour and not bitter) they can be eaten raw. Otherwise, they’ll need to be cooked to help neutralize some of the acid — not the best way to eat dock. more on that below.
Try harvesting dock leaves as early as you can find them (early spring) when they’re still tender and not yet as bitter.
Pick only the smallest rosette leaves — the ones that are still rolled up or have just unrolled — and sample them before throwing a bunch raw in a salad.
If the leaves or stems are still slimy, they’re still tender enough to eat raw.
Slimy leaves don’t exactly sound appetizing, but that’s when they’re at their best. I like to munch on them straight from my garden at this stage.
If the leaves are so bitter that you need to cook them to make them tender and palatable, you’ll end up with a slimy mess.
Some people do boil them in several changes of water, but it’s not worth it to me. If I can’t find young leaves that are tender and mild, I would rather look for something else to forage.
The mucilage may be good for thickening things like stews, though.
The leaves will remain bitter through the heat of summer and into early fall, but frost will render them edible once again, offering them up as a fall green until they disappear with consistently cold weather. Or you may find dock throughout the winter in warmer climates.
The seeds and stems are also edible. The stems are definitely worth eating. They’re usually suitable for eating (for a while) even after the leaves have gotten too tough.
Look for pliable stems that have not gone to flower yet, which is normally late spring/early summer. Once the flower appears, the stems will be tough and fibrous, which makes it unfit for eating.
Even before it flowers, you may need to peel the outside of the stem to get to the more tender, edible core.
Curly dock flowers and seeds
Eating the seeds is another story. It’s really easy to harvest a bunch of them at the end of summer (and sometimes into winter).
It’s not easy separating the tiny seeds from the chaff, though. Everyone I know of who eats or has eaten them, has resorted to grinding seed and chaff together into a flour.
The chaff can be bitter, which of course makes the whole thing bitter, but if you don’t mind that, go for it. And if you know of a good way to winnow the seeds or remove the chaff, please let me know.
Curly dock seeds
Broad-leaved dock, aka Broadleaf dock or Bitter dock (Rumex obtusifolius) is another introduced species that’s comparable to Curly dock in flavor and palatability.
Visually, the biggest difference is the shape of the leaves. Broad-leaved dock has wider leaves that start out as heart-shaped to oval and get more elliptical or lance-shaped as they get bigger.
Its leaves do get slightly wavy as they get bigger, but the leaf margins are generally flatter than those of Rumex crispus.