One of the most daunting parts of making a new flower bed from the grass in your lawn is removing the grass. If you're not in a hurry, you can use a simpler process called "lasagne gardening" or "sheet composting." It is simply a matter of layering the right materials at the right time, so the grass decomposes and becomes the perfect foundation for a new flower bed. Make your lasagne bed in the fall while materials are abundant. By springtime it will be ready to plant.
Mark out the edges of the new flower bed, using a hose, string or spray paint. Cut a 2-inch-wide trench into the grass area 3 to 4 inches deep, using the shovel or edger.
Spread sheets of newspaper over the entire area. They should be about seven to eight sheets thick. Don't use glossy advertisements; use black-and-white traditional newsprint paper. You can also use a single layer of cardboard. Both are biodegradable and aid in the decomposition process.
Water the paper material thoroughly.
Add at least 6 inches of leaves from fall cleanup on top of the newspaper or cardboard. Small leaves that decompose quickly do not have to be shredded. Oak leaves decompose slowly and must be shredded first for best results. Unless you live in a heavily wooded area, this may be a good time to visit neighbours and offer to remove their raked leaves.
Add a few inches of grass clippings saved from summer mowing. The grass can be partially decomposed.
Sprinkle blood meal, compost activator or compost lightly over the area to speed up the decomposing process.
Water the area heavily to start decomposition as well as keep the leaves from blowing in the wind.
Cover with an inch or two of bark mulch if you want to improve the aesthetics. This step is optional, but if you don't get snow cover in your region to hide everything, the lasagne bed can be a bit of an eyesore.
Wait for spring to plant your flowers or seeds, as the new flower bed is ready to use. While some compost material may not be fully decomposed, the grass should be dead. You can add some topsoil to the immediate planting spots if you wish.
Don't underestimate the amount of materials needed. A 100-square-foot flower bed will require large amounts of newspaper, grass clippings and leaves. So you don't run out of materials, start with a small area first and assess the quantity of materials you have on hand before committing to a large area.