Clay soil is the bane of many a gardener's existence. Although it can be rich in nutrients, the individual soil particles are so densely packed together that it can become almost impossible for air, water and tender young plant roots to penetrate. Amending clay soil properly can take years, and is generally done every growing season. It is possible, however, to soften the soil enough to work it in just a few hours.
Dig into the soil 6 inches. Grab a handful of soil and squeeze it in your fist. If it crumbles when you open your fist, it is safe to work. If it remains in a lump, you must wait several rain-free days to work the soil. Working on wet clay soil will cause it to compact.
Rototill or dig into the soil with a pitchfork to a depth of 12 inches. If using the pitchfork, use the back of it to crush any large clods of soil.
Add 3 inches of redwood shavings and 3 inches of compost to the soil and mix it in to a depth of 12 inches. It is important that the amendments are mixed thoroughly with the existing soil, otherwise water may not be able to penetrate.
Rake the area level, and water until the top 5 inches of soil is wet.