Expanding the Garden
Too many beautiful plants and not enough room. So you decide to expand the garden. But first you need to kill of the grass.
Lay out a rope or garden hose to help you determine the size and shape of the expanded garden. Then get out a shovel and start edging. This creates a clean division between the lawn and your garden. It also cuts the roots and rhizomes preventing outside support for the grass and weeds you are trying to kill.
Use newspaper and organic mulch to kill the existing grass without the use of chemicals. Spread a couple sheets of newspaper over the grass and anchor in place with shredded leaves, woodchips or other organic mulch.
Over time the grass will die and the newspaper will decompose adding organic matter to the soil. Now you are ready to plant. Just dig through the grass and mulch.
A bit more information: For quicker results use a sod cutter to remove the existing grass. Use any weed-free sod to fill bare patches and thin areas in the lawn. Or place the sod pieces, grass side down, in the compost pile. The sod will eventually break down and can be returned to the garden in the form of compost.