Question
QUESTION: I planted ground cover last spring which is spreading quite nicely.  I even planted it by poking holes in the weed protector which is covered by a few inches of mulch. However, during the summer the weeks sprang up in the holes and everywhere else. I hand-pulled them as well as applied roundup where i could, but over this winter, they have sprung up everywhere.  Is there any product that i can spray all over to kill the weeds (which include dandelions) without harming the ground cover?  I planted wintercreeper (i think that is the name of it.)  the weeks are so bad now (mostly low weeds) that i cant get them all and it is just a continuous process. how long will it take for the ground cover to choke them out (if ever).

ANSWER: Hi Terri,
Thanx for your question.  You can use Preen?which will prevent ungerminated seeds of weeds from sprouting.  I know of no other type of weed killer that would differentiate between a weed an your ground cover.  You will probably have to continue to spot treat until your ground cover is well established.  You may want to consult with your local county extension agent.  If you need contact info, give my your county and state and I will provide the information.  I hope this helps.
Tom

---------- FOLLOW-UP ----------

QUESTION: What do you you know about Treflan?  Is this a viable alternative? Or is is just to put on the ground before planting to prevent weeds from germinating?

Thanks so much for your quick response. Now if you can tell me how to get rid of torpedo grass in my lawn, I would worship you as a god!!  I was told the only way to get rid of it was to move!!

Answer
Hi Terri,
Thanx for your question.  Treflan?is a pre-emergent for grass and broadleafed weeds.  I do not recommend its use.  I think it is dangerous and not at all good for the Earth compared to some of the other chemicals a person could use.  I am not against chemicals, just certain ones and this happens to be one of them.  Basically, Preen?is a pre-emergent too.  These chemicals prevent seeds from germinating.  Treflan?can damage perennial plants and good-grasses if applied incorrectly or at the wrong time.

I have an article here from Mississippi State that corroborates my suggestion to spot-treat.  I'm sorry there's not an easier way to take care of torpedo grass other than poisoning the whole lawn and starting all over.

We have  big problem with thistle here and years ago, I had a rental property in which the back yard, though small, was full of thistles, plantain, dandelions and other difficult weeds.  We rented part of this property to a woman who mowed all the weeds down and then periodicaly, would go out and spot treat weeds as she saw them.  Terri, by mid-summer, she had a green, verdant, shimmering, weed-free back yard that was just absolutely gorgeous.  I have spot-treated my flowerbeds because of bindweed (another obnoxious weed that is almost impossible to control.).  I hope this helps.
Tom

http://msucares.com/lawn/garden/coast/08/1103.html