Turf Out Now!
Fall is the Perfect Time for Smother Mulching.
By Rachel Foster 10/12/06

Let's say you have decided that the front yard should grow vegetables next year, not turf, or that the grass at the edge of your yard could make way for big perennial border or a mixed hedge for privacy, ornament and wildlife. Perhaps you have a steep, grassy bank you're sick of mowing, and you'd like to replace the grass with ground covering plants or simply with bark mulch. Whatever the renovation you have in mind, the first step is to get rid of the grass.
I'll assume that you would like to do this without herbicides, without renting intimidating machinery such as a heavy rototiller or a turf cutter and without hauling all that turf away to the landfill. Recycling yards won't take turf, and it's a shame to waste it: It may well contain some of the best soil in your yard, not to mention all that free organic matter. There are at least three ways to get rid of grass. One: Trench the area methodically by hand, burying the turf 15 inches down and putting the top six inches of soil back on top where it belongs. Two: Strip the turf away with a straight edge spade, stack it grass side down in a pile to rot and then turn over the exposed ground with a shovel or a light tiller.
The third method, smother mulching, is much less work, and fall is a very good time to do it. You will be killing the grass primarily by depriving it of light. Here's the technique I've relied on for decades.
1. Cut grass (or weeds!) as short as is practical.
2. Check to see if the soil is moist. If it isn't, water thoroughly.
3. Sprinkle a light coating of garden lime or lime-containing organic fertilizer (optional, but it speeds decomposition on acid soils).
4. Lay newspaper four to six sheets thick. Preferably, do not separate pages, but handle several sheets as one unit. The New York Times works really well. Some people use cardboard, but newspaper does a neater job and is easier to lay if the ground is uneven.
5. Overlap adjacent sets of sheets by 4-5 inches. Don't scrimp! If necessary, sprinkle a little soil, sand or gravel to hold the newspaper in place.
6. Dampen the newspaper lightly with water using a soft-spray hose attachment or sprinkler can.
7. Cover with at least 3 inches of bark mulch, soil or compost; 4-5 inches of wood chips; 9 inches of fall leaves; or 2-3 inches of gravel. Start with the area closest to you. Once the mulch is in place, you can walk on it, but don't try to walk on the damp paper before you cover it!
8. Water the entire area to ensure the mulch is moist. Moisture helps retain the integrity of the "sandwich" and is vital to success.
Where the turf you are eliminating adjoins a flower bed or concrete, dig a narrow trench and fold the edges of the newspaper down into it. Fill the trench with sand or mulch to hold the paper down.
If you are treating a large area, you can do it all at once and have the mulch or soil blown in. But this does require that you have perfect weather conditions and time to lay a lot of newspaper while keeping it moist and intact until delivery. If you do all the work yourself, it may be easier (and definitely cheaper) to lay down small areas of paper or cardboard and cover with mulch as you go.
The time it takes to kill the grass varies with season and weather. I prefer to leave it for several months and then till it all together. (If you are tilling in bark mulch prior to planting, it is a good idea to add a nitrogen-rich material such as alfalfa meal to offset temporary nitrogen depletion.) If you are planting shrubs, you can leave the mulch layer largely intact and just make planting holes where you need them.
I have found the method extremely effective at killing virtually all lawn grasses I've encountered as well as most common weeds. (It will not kill horsetail or bindweed.) People occasionally tell me it didn't work well for them. Having watched some smothering in progress, I have concluded that the most likely reasons for failure are three: Not enough moisture in the ground or in the mulch; not enough overlap of paper; mulch layer not deep enough. Because the integrity of the cover is essential to success, very uneven ground can present a problem, so fill noticeable depressions in lumpy ground with sand or clean soil before you lay the paper. Mend squirrel divots often, and keep the area moist.