Just like Esshup says you have to hit them with the appropriate product as soon as they appear. The problem is they spread via rhizomes (extending root runners) not just seeds. At some point you will see very few and it won't be much of any issue to spray anything that pops up.
I used to have major problems with them. After nailing everyone I can two years in a row I hardly see them anymore.
I also cut them down and remove them once the plant turns yellow from the herbicide.
Last edited by Cecil Baird1; 12/20/10 09:16 PM.
