Cardboard laid over any plant, grasses or whatever, will keep those plants from getting access to the sunlight they need to grow so, yes, the grass plants under the cardboard will die. There is no reason to wet that cardboard before laying it down but you do need to cover it with some material to hold it in place.

Landscape fabric would not be needed since the grass, unless allowed to grow, would not be setting seeds.

kimmq is kimmsr

Hmm... that's good news! So there wouldn't be dormant seed left over from prior years? I just need for the weather to cool off so I can get started! So. CA has been miserably hot this summer/fall so far.

Clipdrop.in would love to help you smother that grass completely

I tried googling it, no idea what that is. Can you explain or link to something?

This is probably a little late to me in. . . did you complete our project? Did it work?

I have never used that method on the entire lawn, however I have and still do use it to make flower beds. I hate to dig/haul off sod and till. Plus I like my flower beds even with my lawn for easy mowing. I discovered the technique here on GW. its called lasagna beds. My yard didn't have a single flower bed when we moved in, now I have a plenty **too many**.

The method calls for organic matter in layers, hence the name. . . alternating green and brown. . . I used cardboard, leaf mulch, saw dust, fresh grass clippings and manure. I ended with top soil and was able to plant in them right away. They seem a little **raised** at first but the break down with watering and winter.

That's great! About how long before you can plant in these beds? I've read the cardboard method takes about 8 weeks. Also, do you have issues with weeds later?

I still need to do this, but I'm getting closer!

the flower beds can be planted in as soon as the last layer is on. The layers don't get removed. They become your bed. That's the beauty of lasagna beds, they are instant beds ! As the somewhat raised bed gets watered and starts to compress the plant/roots go down with it, finding their way to the ground. I watered after each layer and kept it well watered as the raised beds dry out quicker than in the ground. I don't really have a weed problem. Once you get your project completed keep reading in this forum for very good advice on caring for your soil which will result in a lush lawn and few, if any, weeds.

good luck !

I do this all the time. In a pinch I have used layers of newspapers when I run out of cardboard. Works great. I always water mine down before I pile anything over it. If I'm using newspaper, it's almost imperative to use water because usually the wind decides to blow!

I usually plant immediately. Use an old pocketknife to cut holes in the cardboard/newspaper where you want your new plants, shoving aside the mulch/topsoil/whatever you put on top. Then after your plant is in the ground, push the mulch, etc. back around it.

I don't push/cut the cardboard away. The CB will break down before the roots make it down that far. Even if the roots hit the cardboard its wet and soggy so they can bust thru it. Not saying the other way is wrong, this just how I do it,

When using either newspaper or cardboard (they are really the same thing) I would not plant immediately since it does take some time for the growing plants so covered to die. Most of the covered top growth should be dead in about two weeks but it may take several more weeks for the plants roots to die, and with some invasive grass species (such as quack grass) that may never happen.

kimmq is kimmsr

Well, this is great! I think I'll just do this a patch at a time. Eventually I'll have the whole thing done!

I did this last spring to kill the buttercup invading my lawn from the adjacent ditch. Covered the cardboard and newspaper with 4-6 inches of bark mulch which looked boring last summer, but worked like a charm. Created a very long border bed I'm planting this year and the soil is much improved. All trace of the cardboard is gone and the worms have moved in. Even by last fall, when I planted some blueberries, the cardboard had disappeared. I did have to hand pull buttercup that had migrated to the edges, but that wasn't too bad.