Mugwort Invasion

Question: My plant app identified this as mugwort. It is spreading uncontrollably through my garden beds. I have dug some out and tried to pull rhizomes from the soil. My lawn service person has cut them short and sprayed them two times. They keep growing back and spreading to landscape beds around the yard. Do you know how to eradicate them? Thanks so very much. I have a dog so I like to use chemical sprays as little as necessary.

responder: Answered by theHome and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied June 29, 2023, 11:37 AM EDT
response: Here is our page on Mugwort (Artemisia vulgaris):  https://extension.umd.edu/resource/mugwort  It is an invasive plant that can be challenging to control. What chemical did your person apply? A systemic herbicide containing the active ingredient glyphosate or triclopyr should work. (You don't want to contact desirable plants) Carefully used by following all label instructions and allowed to dry, it should not be of concern for your dog.   Christine

responder: The Question Asker Replied July 11, 2023, 10:56 AM EDT
response: Hi Christine: I sprayed and it looks like the mugwort is dying off. Should I dig up the plants and roots? I want to plant ground cover in the area. I have another question. Phragmites spread from my neighbor's property to an area of sand/mud waterfront. A company sprayed our area and I cut back the dried/dead canes. A few plants are beginning to grow: River Bulrush, Hedge bindweed, and Turks cap. Are they good plants for a marshy area? Any suggestions for putting some native plants in the area. One problem I may have is if the neighbors don't control their phragmites, it will keep invading this area. Thanks so very much.--Robbie

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 11, 2023, 2:58 PM EDT
response: Hello Robbie,  We recommend waiting for at least a few days (maybe over a week...see if the label says how long) after treatment before attempting to dig-out the dead Mugwort. Complete root death might take some time as the herbicide makes its way from foliage into roots, so symptoms in the foliage doesn't always mean the roots have fully succumbed yet. Pulling them up too soon may leave viable root pieces left that can resprout, though it would not be unusual to have to re-treat at least once more anyway if resprouting occurs. You do not have to dig up the roots on dead Mugwort if it looks like it's not coming back; it will decay in place and not bother any new plantings.  Phragmites might return if, as you pointed out, a nearby population isn't kept under control. At best, you might at least be able to stop creeping roots by burying a rhizome barrier (similar to what is used for containing bamboo, but likely less deep) but this might take more effort than it's worth if some spreads by seed as well and can just blow in.  River Bulrush is a native plant and should be fine to keep. Hedge Bindweed is a common non-native weed and should be removed, though this too might involve repeated pulling or careful spot-treatment with systemic herbicide because established bindweed plants can be hard to manage. Turks-cap Lily appears on its own less often in home landscapes but it is native and a good wildflower to keep if it volunteers itself. They look similar to the non-native Tiger Lily, which we would not recommend keeping, and a bit less similar to (but sometimes confused with) a particular species of Orange Daylilies which are invasive and should be removed.  There are a number of other Chesapeake-shore / coastal plain native plant species you can choose from depending on what is suitable to your site conditions. You can explore resources like the links below for some candidates: Native Plants for Wildlife Habitat and Conservation Landscaping: Chesapeake Bay WatershedNative Plants of MarylandLandscaping with Native Plants  Miri