Our native plants are not weeds. Weeds are aggressive invaders, often brought to this country in animal feed. Many plants that you might consider native, especially grasses, endemic in natural areas are actually weeds that came with the stagecoaches. The most troublesome weeds in our gardens are foxtail grass, oxalis species, and milk thistle. Persistant removal by hand, especially before flowering, is the most effective way to get rid of weeds. Oxalis may require chemical destruction. Bear in mind that it is difficult to control Roundup spray which often will kill a cherished plant growing beside the weedy target. A small paintbrush is a good alternative method of applying Roundup.
There are other kinds of weeds too. Lamb’s quarters is a common weed that is also edible. It is difficult to eliminate if it goes to seed, but if you eat it when it is young it won’t get a chance to seed! Chickweed is another common edible weed that is fodder for birds as well as having tremendous nutritional properties for humans. I tried some recently and it is a delicious addition to a salad. Chickweed water is said to be a cure for obesity! Chickweed spreads rapidly if unchecked.