I'm going to attack a Nutgrass infested area today using the some of methods recommended on this site. I believe one technique mentioned is to cover the affected area with newspaper and then more soil. My assumption is that this smothers the grass as well as blocks moisture from getting to it.

I have an abundance of cardboard from boxes that are used for packing and shipping that I'd like to use in place of the newsprint. Perhaps this is splitting hairs but is this too much of a barrier? I plan on adding 6" of new bedding mix over the cardboard and replanting the garden with natives and wonder if the barrier might be too good, preventing proper root growth of the new plants. Seems to be a catch 22, stop the Nutgrass from growing up through the new soil yet the new plants will certainly want to grow through and below the barrier. In the case of some plants I might have to punch through the barrier just to plant the properly.

Timing seems to be the issue. Hopefully the Nutgrass dies before the plants want to root below.

So what to do you think? Cardboard or newspaper? If newspaper, how many layers might be adequate?

Thanks, Stuart

Neither one will work. How often does your nutgrass area get moisture? and how much does it get?

The area I'm battling has had no supplemental moisture this season, only rain. I've just finished with a 4 tine garden fork turning the earth over to 6" deep and removing every visible speck of Nutgrass I could. Today my plan is to soak the existing soil with liquid molasses then add more soil, building the beds up to promote better drainage for the natives I'll plant back. Not sure now if I should place the barrier down before the new soil or not.

If the barrier method won't work perhaps Howard needs to remove that advice from the library?

Hey stuart this is in a flower bed?

Yes, smack dab in the front of the house.

Well you could sheet mulch it with 3 - 4 sheets of wet news paper then go over it with nice looking mulch, but for nutgrass, you might have to do the whole bed and not just the "infected" area.