Loosen the soil along the dead area of grass with a garden fork. Stick the fork tines into the ground and rock the fork back and forth. Lift up the soil and loosen all of the sod along the row where you plan to plant the sunflowers.
Mix in compost as you turn the soil over with the garden fork. Work the soil along the row until it is loose and can be easily worked with the fork.
Rake over the row of prepared soil with a bow rake to smooth out the surface. Make a 4-inch-deep furrow in the center of the row with a hoe.
Plant seeds in the center of the furrow approximately 6 inches apart. Cover over the seeds with 1/2 inch of soil for small varieties and 1 inch of soil for larger varieties of sunflowers. Pack the soil down with your hands.
Water the seeds thoroughly using a watering can. The seeds will germinate in five to 10 days. Once the plants start growing, you can fill in the sides of the 4-inch furrow over the stem to provide additional support to the stem and promote a strong root system.