Oats are technically cool season annual grasses, growing 24 to 60 inches in height. As a popular food crop, almost every state it the United States and most countries around the world grow it. This plant is only moderately resistant to cold but works as a winter crop in the South where they rarely experience hard freezes. Oats can tolerate almost any soil type, but in order to grow them effectively in clay, you must first amend the soil.
Chose an area in early spring to plant your oats, making sure it gets a few hours of sun every day. Place a sample of the soil from that area into a container and send it to your local extension office. They will test the soil for you, telling you what nutrients you need to add.
Dig the soil to a depth of 8 inches, breaking up clods of clay. Lay down a 2-inch layer of decomposed organic material and mix it into the soil. Make another 2-inch layer, this time including any of the nutrients the extension office suggests for your soil, and mix this in as well.
Plant oat seeds 1 inch deep. Water them slowly after planting, making sure the water seeps into the soil well.
Keep the oats moist through the growing season. Oats can withstand wet soil conditions better than other grasses, but they need more moisture than other grasses as well.
Apply a fertilizer after the oats start growing vigorously. Use a complete fertilizer marked 10-10-10 (10 percent nitrogen, 10 percent phosphorous, 10 percent potassium), and follow the instructions on the label.