Mallow is driving me crazy! We can’t get rid of the stuff! So this year (that indicates that we’ve been at this a while) we think we’re going to outsmart it. First, since the stuff just doesn’t die, frost, intense heat, dogs, and so on, we’re going to yank as much out now with our hands covered in mittens and heads in warm fleece caps with hopes that NO seeds will develop or fall into the frozen ground.  Ha! Next, we’re going to cover the ground, AGAIN, where it was growing, with cardboard or old karate mats (yes, old karate mats). Third, we’re going to plant something else on the ground as a cover, or actual landscaping, anything once it’s warm enough for anything else to survive. I tell you, this stuff could grow in the Arctic or the Sahara! Arrrghh! Mallow, you are my nemesis!

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74127.html