Dandelion and Common Purslane: Ubiquitous Edible Weeds

Dandelion

Dandelion (Taraxacum officinale) is a perennial weed that self-seeds readily. A single specimen can live from 10 to 13 years. While it tolerates many different growing conditions, it prefers full sun and moist fertile soils. Dandelion is stubborn and prolific. All of its parts are edible, including root, leaves, flowers, and even seeds. This plant is recognizable by most of us through its form, leaf structure, flower, and seed head.

Dandelion has a low-growing basal rosette form with a center crown from which all leaves and flower stalks emerge. Its mature leaves are dark green and range from 3 to 10 inches long. The leaves can vary in form, but are usually deeply lobed.  The margins (outside edges) of the leaves are deeply serrated. The sharp teeth of the leaves point back to the crown. The leaf form is the basis for the dandelion's common name. In French, dent-de-lion means "tooth of the lion." The largest lobe is usually at the end, the tip, of the leaf. The rosette can stay green through mild winters or disappear until early spring.

The round ray flower of the dandelion emerges from the crown on a hollow leafless stem. It is a beautiful bright yellow flower, 1 to 2 inches wide, with many, many petals. Depending on the weather, the flowers can start blooming from May through June and then again in the fall when cooler weather returns. In my lawn, the flowering season for dandelions and violets overlap, creating a very delightful sea of yellow and purple.

Dandelion flowers change, after 9 to 12 days, into very noticeable mature, globe-shaped, puffball seed heads. When ripe, the seeds are dispersed easily by the wind or by children joyously blowing them in the breeze. One flower can produce up to 400 seeds. One plant can produce as much as 15,000 seeds in a season. Seeds can travel for miles in the wind. The stalk actually grows taller as the seeds mature. This increased height gives it a greater chance to find the wind. While the seeds are not long-lived in the soil, they are certainly prolific.

This weed has a very long, strong, fleshy taproot that can grow to a depth of 18 inches. It will easily regrow from an inch or longer piece of broken taproot that has been left in the soil.

All of its parts—taproot, leaf, and flower/seed stalk—exude sap that is milky.

Though now ubiquitous, this weed is not native to North America. It was brought by early settlers from Europe where it had been harvested since Roman times. It has been considered a useful, edible plant for humans and other wildlife, including some pollinators. In the early spring, the young leaves make a very delicious and nutritious salad. Older and more bitter leaves can be sautéed or braised. Dandelion wine is made from the flowers. The taproot can be roasted to make a coffee substitute. Find interesting recipes at Five Ways to Eat Dandelions, Michigan State University.

If you choose to enjoy dandelions as food, know your source. Ensure that they have not been sprayed with herbicides or pesticides and have not been visited by your neighborhood dogs. You can also purchase seed of cultivated varieties from many seed sources. You may want to grow these in a container.

Dandelions grow in lawns, landscape beds, and even between cracks in the sidewalk or driveway. To reduce the quantity of this weed in your garden, pull or dig it up in its entirety. Plan to do this when the soil is very moist, after a rain. Remove all of the taproot so that it will not regrow. Pull it before it sets seed. If pressed for time, remove the flower heads before they mature into seed heads.  You can return later to get the entire crown and taproot. Compost the plant, but not the seeds. Digging tools exist to help remove the entire root. Flame tools on dandelions are not that effective. The taproot remains while the surrounding groundcover has been burnt, leaving a sunny spot for dandelion regrowth.

If you or any neighbor have had dandelions, there is likely to be a continual bank of these seeds on your soil. To reduce its germination rates in your lawn, keep your lawn thick and healthy. Avoid bare spots. A mowing height of 3 inches or more will assist in blocking out the light that helps dandelion seeds germinate.

A 3-inch layer of mulch will reduce this weed in your landscape beds.

Common purslane

Common purslane (Portulaca oleracea) is a drought-tolerant summer annual weed. Its prolific seeds overwinter and begin germinating in late May to early June when the soil temperature reaches into the mid to high 80°F range. They will continue to germinate during the heat of the summer, especially after a rain.

Photo credit: M.E. Bartolo on Bugwood.org

This plant is characterized as a colonizer of bare ground in disturbed sites, meaning it will grow under the most adverse conditions, including on compacted soils and between bricks and cracks in concrete. It thrives in sunny nutrient-rich, sandy soils.

Purslane is a mostly low-growing weed that develops into a dense circular mat reaching 6 inches tall and up to 2 feet in diameter. Its succulent round stems turn maroon as they age. Its leaves are succulent and even glossy. They are green on the upper-side and maroon-colored underneath. Mature leaves are obovate (egg-shaped), can be up to an inch long, and are wider at the tip than at the base.  They have been described as paddle-like. The leaves have smooth untoothed margins and are rounded at the apex (tip).

Purslane's small bright yellow flowers develop beginning in July, just four to six weeks after the plant's life begins. Each flower has five two-lobed petals and is basically stalkless. Instead, the flowers cluster at the tip of a branch or in the leaf axils, the point where the leaf emerges from the stem. The flowers open only when it is sunny. The seed capsules are small, only ¼ inch long, and contain many flat black seeds. The seeds are only 1 mm long, the size of a pencil-tip. A good sized-plant can produce up to 240,000 seeds in a season. The seeds can remain viable for up to forty years.

Purslane has a taproot with some fibrous secondary roots. Stems can root when a node touches soil.

Purslane is native to India and Persia but is now widespread throughout most of the world. It was cultivated in Plymouth Colony in New England as early as 1631. The succulent leaves and stems are prized as crunchy and nutritious, a rich source of vitamins A and C as well as omega-3 fatty acids. Use them in salads and on sandwiches. Purslane stems and leaves are also mucilaginous (gelatinous/viscous), meaning they can be used to thicken soups and stews. As with any foraged edible, know the source of the weed and ensure that it has not been treated with chemicals. Cultivated varieties are available from select nurseries and seed companies. Find a number of recipes for purslane on the Horticultural Promotions for South Central Texas website. 

Pulling purslane is the best way to remove this weed, preferably after a rain when the wet soil will release the taproot more easily. Remove the weed when it is young, before it sets flower and seed. You can add the plant to the compost pile as long as it hasn't set seed. Do not leave remnants of the plant on the garden bed because moisture remaining in its succulent leaves and stems can be used by the plant to develop new roots. It can regrow where it touches the soil.

Maintaining a dense healthy lawn with no bare spots will reduce its likelihood of germination. Likewise, mulching landscape beds and vegetable gardens will keep sunlight from the seedbank, preventing germination.  Be aware that tilling can bring hidden seeds to the surface. And, remember, the seeds of common purslane can remain viable for up to forty years.