Clay soil is naturally made of tightly structured, little particles that make water drainage and air flow through the soil hard. It takes up to four times more water to saturate clay soil than other soil types. Once soaked, the clay soil holds water, causing most plant roots to become dysfunctional and prone to decay and disease. But there are lots of perennial plants available for example; black-eyed Susan (Rudbeckia), daylily (Hemerocallis) and fountain grass (Pennisetum) that are hardy to U.S. Department of Agriculture plant hardiness zone 10 and can tolerate growing in clay soil states.
Moisten the clay soil to a depth of 6 inches, in many intervals to steer clear of runoff, with a watering hose 48 hours prior to digging. This will definitely soften the compacted soil and improve water penetration depth, making it less difficult to dig in the ground.
Pass an aerator that pulls 3- to 4-inch soil plugs above the moist ground several times and in various directions, twice a year. This leaves behind little holes in the ground that will enable nutrients and air to mix with the clay soil.
Apply 1 pound per 5 square feet of gypsum in addition to the ground in rows with a broadcast spreader, twice a year. The University of California and the University of Illinois Extension note that gypsum is rarely helpful to the soilnonetheless, it helps by getting in between the clay particles and loosening the ground to get easier digging and better air flow. Gypsum may dissolve when mixed with water, so the benefits could be temporary if rainfall and irrigation are prevalent. Assess the width and length of the yard, in feet, and multiply them together to have the square footage of the area.
Utilize a spading fork into the ground to a depth of 2 feet, turning and breaking up any large clumps of clay with the fork. Allow the turned soil to dry approximately 24 hours and then repeat the procedure till all of the clumps have crumbled along with the soil is easily dug with a shovel.