If gardening soil is too heavy, it presents several challenges as you try to grow plants in it. Not only is the soil difficult to work, it retains moisture due to poor drainage, creating a compacted soil that is a nearly impenetrable growing environment for plant roots. You can correct a heavy clay soil by improving its soil drainage with organic material. By mixing organic material into the soil, it becomes lighter and rich with nutrients for your plants.
Work the soil with a garden spade or fork to loosen it to a depth of about 6 inches.
Add at least 4 inches of aged compost or peat moss to the soil, spreading the compost in an even layer.
Spread 2 inches of coarse sand over the compost in an even layer.
Work the amendments into the soil with a garden spade or fork, working the soil until the ingredients are completely incorporated.
Rake the soil surface smooth to finish amending the soil.