Mulch can be compost, straw, shredded newspaper or grass clippings. Use small amounts at a time. Too much at one time can cause mold and rot problems. Run water slowly and allow it to soak in to the ground to root level. Plastic mulch around vegetables saves water, promotes early growth and cuts down on weed establishment.
Excess water can cut production.
Sink a shovel in and open ground enough to observe. Then lay the soil or sod back in place. Once you have done this, you will have a good idea whether the water is reaching the depth you desire. Garden and yards soils average about 5 inches of water-holding capacity. Under good water management, you can expect to replace no more than 50 percent of this.