Things You'll Need
Hose end sprinkler
Hardpan soil is soil that is so compacted that water may not be able to penetrate. Often it is clay soil that can dry to rock hardness. One of the major problems with dry, hard soil is that it will not permit plants to grow well because the roots may not be able to push through the hard soil. When the roots can push through the soil, there is no water for them to find. But you can fix a dry, hard lawn by amending the soil.
Loosen the soil with a spade by driving it down into the soil to a depth of 12 inches. Wriggle the spade back and forth to create air pockets in the soil.
Cover the soil with a 4-inch layer of compost and peat moss. These ingredients will help to add air into compacted soil, which will loosen it. The organic amendments will also retain water in the soil.
Rake these amendments into your soil with a leaf rake. Comb at the soil to force the compost in between the grass stems and down into the soil line. The compost will work its way into the opened pockets of air.
Water your lawn using the equivalent of 1 inch of rain per week with a hose end sprinkler. Use a rain gauge to determine how much water you have used.