MUGWORT AKA Artemisia vulgaris

Mugwort is native to temperate areas of Europe as well as Asia. Historically this plant was used to cure so many ills that during the Middle Ages it was called "The Mother of Herbs". There are a number of different plants in the Artemisia family.  Of these, mugwort is the most common variety.  When you see the Latin word vulgaris incorporated into a Latin name for a plant it simply means common, or the most commonly found variety. In addition to medicinal use, the plant was used as a flavoring for beer before hops and it was and still is used in various foods where a somewhat pleasant but bitter flavor was desired.  Because the plant had so many different uses, it was deemed a necessity in the North America.  Therefore, the seeds hitched a ride with passengers headed here as early as the 1600's.  Once mugwort arrived on our shores it readily colonized, and then it naturalized.  This plant rapidly creates a monoculture.  

I have actually watched it happen right under my nose! The bridge spanning Merrick Brook on Station Rd. was replaced around 12 years ago.  The soil was disturbed in the process and after the work was completed, a grass seed mix was spread to suppress erosion and presumably weeds, but somehow mugwort sprouted in the disturbed soil.  I think because the plant so strongly resembled ragweed, I did not notice its presence.  Once the plant had begun to invade my yard and gardens, I looked at it more closely and realized what it was.  By that time, it had begun to spread significantly along both sides of the road.   When I tried pulling it out by the root, I realized what an extensive rhizome system it had. It is extremely difficult to remove the entire root system from the soil without leaving a portion behind.  At first, I thought perhaps cutting the plant back would help keep the plant contained, but by the time I got out my weedwhacker the plant had developed tough reedy stalks, and the mugwort just laughed at me.  After years of growing unchecked, the mugwort colonies along both sides of the bridge appear to be bursting through the guardrails. 

Large colonies of this plant can be seen growing along roadsides all over town.  Like many of the plants I've been writing about, mugwort contains allelopathic compounds, chemicals exuded from various parts of the plant which prevent other plants from growing nearby.  Despite its legitimate uses, mugwort has definitely achieved outlaw status, not only because it chokes out native plants, but also because it does not support any of our native wildlife.  The pungent medicinal fragrance contained in its foliage deters grazing animals and insect life from consuming its leaves.  Its flowers pollinate by wind therefore mugwort does not support any of our native nectar seeking insect life either. The plant rapidly spreads from its creeping rhizomes as well as from seed with one plant producing up to 200,000 seeds per year!  Fortunately, not all of these seeds will be viable, but then it really only takes one to germinate and rapidly create a new colony.  

HOW TO REMOVE

Hand pulling is an option for small infestations, again best done after a good soaking rain which softens the soil making rhizome removal easier, also gloves and long sleeves recommended due to potential dermatological reaction.  Larger plants have an even more tenacious rhizome then their younger counterparts making hand pulling quite a chore.  Mowing the plants back early in the season and then smothering the colony with heavy duty landscape fabric or a layer of cardboard followed with a very thick application of mulch may help but the area will require monitoring. Mowing the plants with a brush mower in mid-September before seeds mature will at least eliminate seed dispersal. A foliar spray containing triclopyr applied on the mature plant seems to be one of the more effective treatments recommended for this plant's permanent eradication.