Beauty is in the eye of the beholder. Mugwort (Artemisia vulgaris) is a persistent weed but it is also a member of the Artemisia family of healing and beneficial herbs, with Sweet Annie being one that is commonly grown. Mugwort has no major herbal qualities but it has a pungent scent and has been used to flavor beer. Mugwort control is a challenge due to its hardiness and spreading rhizomes. Controlling mugwort will likely take chemical agents unless you are patient enough to pull the weed annually.
About Mugwort Weeds
Prior to a big kill campaign, you should know your enemy. Mugwort leaves look like chrysanthemum leaves with smooth dark green upper leaves and a lighter green underside that is hairy. The hairs have a whitish cast and give the leaves the impression of being silver. Leaves are elliptical and deeply notched and grow 1 to 2 inches long.
Mugwort weeds are sprawling, spreading plants that bloom from July to September. Flowers are multiple clustered yellow discs on a flat base. They eventually produce small inconspicuous brown, nut-like seeds. When crushed, the leaves produce a strong aroma, somewhat like sage.
The plant is a perennial, which favors ditches, fields, along roadsides and paths, and most disturbed areas. It will even grow in turf where mechanical control is nearly impossible. The plant has some history of dermatological toxicity in some individuals. Once mugwort gets a toehold in your garden, it will spread like wildfire through the root and underground stem system but also from seed in warm regions.
Controlling mugwort will require persistence if a natural route is desired. Over the seasons, you can manually remove the plant which will deprive the roots of solar energy and eventually kill it. This is tedious and time consuming but comes with the added bonus of not increasing your chemical footprint on earth.
In turfgrass the best defense is a healthy lawn. Choose a dense variety of grass and fertilize and mow with regularity to keep it thick and resistant to weeds. More vigorous methods will require chemical applications and these often necessitate repeat treatments to completely kill mugwort plants.
The use of thick mulch in garden beds can prevent germination of some of the weeds and keep spread down.
Chemical Mugwort Control
Getting rid of mugwort organically is a challenge. There are no recommended pre-emergence chemicals which would allow you to kill mugwort plants before they emerge. Dicamba, glyphosate and 2,4D are all used in commercial agricultural fields to kill mugwort plants and other pest plants. Glyphosate is non-selective and can kill wanted plants, so caution is advised.
Control from these chemicals is not even that adequate, but they are useful in areas where you cannot completely eradicate all plant life. If you have an area that you can do a complete rejuvenation on, simply spread a black tarp or cardboard over the area and smother the pesky plants.
Getting rid of mugwort is a test of patience and dedication but its spreading habits leave little other choice.