Weeds by definition are undesired plants in
undesired areas. While some are truly pernicious, most are simply under utilized. Living in a urban environments limits ones ability to collect wild mushrooms, herbs, and edibles, but there still is a free abundance for anyone that looks. Weeds are plants you just haven't met yet, and eaten. *nom nom handshake nom*
Dandelion is a well known weed that has many uses, medicinal and edible. Its good for greens when young (less bitter but older plants are good for a hearty stew or stir-fry), and coffee like tea can be made from the root (simply clean it, cube it, and then bake it in oven until dry, crush it up and steep). Purslane also provides nice greens and micronutrients not often found in traditional vegetables. Plantain is a known herbal medicine that can be used as a general anti-toxin against a host of ailments, and the leaves are a good source of B1.
Our first foray into this world of foraging was with little bittercress. It grows as a small cluster of stems with one large leaf surrounded by several leaflets, and when in bloom one shoot with multiple flower heads sticks straight up. The roots are shallow, and it is ubiquitous in Portland. It is an edible microgreen with a flavor like a nutty spinach. To prepare it I simply washed the greens thoroughly and removed the roots (although they probably are also edible, I just was lazy about washing the dirt off) Later this was cooked into a stir-fry and it was delicious.
All those bare spots in our garden growing weeds, are just growing another source of nutrition that requires some simple harvesting. Although I wouldn't recommend taking edible weeds from anther's yard due to possible contamination by herbicides or other chemicals. Also, make sure you know what you are eating. Posting on facebook after the fact is not fail safe method.
2 days ago