This weed has been like a mythological pestilence. When I roto-till, I chop up the roots of this noxious weed and a new plant arises from each piece. Too many to pull -- not that the roots come up with the plant. Too resistant to mulching. And too resistant even to herbicides -- not that I want to use those in my vegetable garden.
I've identified this bane of my existence, and its name is Mugwort.
Here's an encouraging little piece on its prevention, control and management that I found:
The dense root system of mugwort can make it difficult to control. Pulling is ineffective, and may even promote growth by leaving residual rhizome fragments in the soil. Mugwort tolerates mowing, and even sustained mowing over two years will not fully eradicate mugwort stands. The relatively shallow roots make mugwort vulnerable to repeated cultivation in agricultural systems, though this practice risks spreading root propagules.Ironically, mugwort was used in the Middle Ages as a magical protective herb. Mugwort was used to repel insects – especially moths – from gardens. This was before roto-tillers.
Interestingly, mugwort has a long history as an herb. WebMD has this to say:
People take mugwort root as a “tonic” and to boost energy.
People take the rest of the plant for stomach and intestinal conditions including colic, diarrhea, constipation, cramps, weak digestion, worm infestations, and persistent vomiting. Mugwort is also used to stimulate gastric juice and bile secretion. It is also used as a liver tonic; to promote circulation; and as a sedative. Other uses include treatment of hysteria, epilepsy, and convulsions in children.
Women take mugwort for irregular periods and other menstrual problems.
In combination with other ingredients, mugwort root is used for mental problems (psychoneuroses), ongoing fatigue and depression (neurasthenia), depression, preoccupation with illness (hypochondria), general irritability, restlessness, trouble sleeping (insomnia), and anxiety.
Some people apply mugwort lotion directly to the skin to relieve itchiness caused by burn scars.Also interesting is the fact that mugwort was a common ingredient in gruit. This was before the "discovery" of hops. Maybe I should return to making beer again. At least my garden would have some use.