ADD ORGANIC MATERIAL WHEN PREPARING SOIL
Once the best location has been selected, begin soil preparation. If you have an established garden area, usually weeds and grass are not present. If tenacious grass such as bermuda is present, it must be removed. Till the area to a 1 inch depth and remove all soil and grass stubble. Do no think that such grasses can be tilled into the soil and disposed of; they will return more vigorous than before. If the grass is dormant, contact herbicides such as glyphosate are not effective.
Till or spade soil when it is moist but not wet. Working soil when too wet can cause large clods and a rough planting surface.
Adding liberal amounts of organic material to all types of garden soils is a highly recommended practice. Hay, compost, rotted grass clippings or leaves applied 2 to 3 inches deep to the garden surface and tilled or worked into the soil greatly improves sands or clays.
Heavy clay soils, which are sticky when wet and hard as a brick when dry, can be modified if large quantities of organic matter and a washed, coarse sand are added. Use a washed sand to insure removal of calcium carbonate, which makes alkaline soils even more alkaline. If only sand and clay soil are mixed the result will be a hard adobe! Quantities of organic matter and sand must be added together to compose a garden mix which is one-third sand, one-third soil and one-third organic matter. For instance, add 3 inches of sand and 3 inches of organic matter to the garden surface if the soil is to be tilled to a 10-inch depth.
Gypsum (calcium sulfate) added to a "sticky" soil makes it more friable. Gypsum is a neutral product which does not increase or decrease the soil's alkalinity. Not only is it a good soil conditioner, but it also furnishes certain amounts of calcium, which may prevent such minor element disorders as blossom-end-rot of tomatoes. Never add lime or wood ashes to alkaline soils.