Before you eradicate them all, please know that if you were to exclude light as they grow so they are blanched they are a pricey delicacy in Asian cooking. The blanching makes them more tender and easier to digest. Sometimes called nira or nira grass. Select young plants, cover with a tallish black plastic pot, place a rock or brick so it won't blow away and wait until the leaves turn light yellow or almost white. (I learn this stuff from my friend Plant Sister who lives half way around the world.)