How to Use Sunflowers as a Cover Crop

Enrich the soil in your planting area by digging one part organic compost into each four parts of soil and mixing well. Choose an area where another type of crop grew previously and where you will not be planting a crop other than sunflowers for several months.

Sow seeds thickly: in field trials, up to 35,000 sunflower plants grew in each acre. Plant in fall if you live in an area with mild winters. Wait until spring to plant if your winters are cold.

Water your sunflowers every week if rains do not occur. Use a drip system to prevent the foliage from becoming wet, which can encourage powdery mildew to develop.

Fertilizer your sunflowers if your soil is infertile, sandy or rocky. Use a balanced plant food with equal amounts of nitrogen, phosphorus and potassium, for example, 10-10-10.

Cut off seedheads when seeds are plump and black. Dry seeds for next year's crop or for eating. Leave the lower portion of the plants in the soil until the leaves begin to turn yellow and dry.

Pull your sunflower plants from the soil after the leaves have turned yellow. Chop up the leaves and stems into 1- to 2-inch pieces. If you have a chipper/shredder, this machine will make the job easy.

Dig the chopped-up plant parts into the soil. Allow them to break down for several months and then plant a new crop in the area.