By
eHow Home & Garden Editor
Difficulty: Moderately Easy
Step1
Understand how fertilizers are rated. Three numbers located on the bag represent the percentage amount of nitrogen-phosphorus-potassium in the mix. A label of 10-15-10 is good to start with in the early spring.
Step2
Go to a garden supply store and purchase the fertilizer when you are ready to plant. A salesperson will help you determine the needed amount based on the area or the number of sunflowers you expect to grow.
Step3
Still fertilize even if you previously planted the seeds and the plants are already pushing through the ground.
Step4
Work the fertilizer into the soil two inches away from the plant or where you planted the seed. If the seed is not yet in the ground place some fertilizer two inches below the seed bed. Don’t place the fertilizer with the sunflower seeds.
Step5
Apply the same method to larger rows of sunflower seeds or plants. Always allow two inches from the growing area. Form a band of fertilizer on each side of the row.
Step6
Water the area as needed.
Step7
Apply additional phosphorus and potassium on the surface either in the spring or fall. Use a broadcast spreader for this. Read the directions for proper setting.