How to Make Sunflowers Grow Fast

Select an area for sunflowers that receives six or more hours of direct sunlight a day. Sunflowers thrive in all-day sun, and hold up well to hot afternoon rays.

Till the soil to a depth of 8 to 10 inches. Remove foreign objects, roots and large stones from the soil.

Spread a 2- to 4-inch layer of compost or well-rotted manure over the soil. Till this into the top 6 inches of the soil. Organic matter improves aeration and promotes drainage.

Apply 5-10-5 fertilizer following the application rate on the container. Work the fertilizer into the soil with a hoe or garden rake to prevent damage to seeds and young roots.

Mark the row for your sunflowers with the edge of the hoe, creating a shallow furrow for the seeds. Plant seeds in the furrow and cover with 1/2 to 1 inch of soil. As a rule, smaller seeds require shallower planting than large seeds.

Space sunflowers to the recommended distance. Giant sunflowers that may tower to 10 feet or more require 2 to 3 feet between plants to produce well. Smaller sunflowers require approximately 1 foot between plants.

Water to moisten the soil to a depth on 1 inch. Keep the area moist until seeds germinate in 5 to 10 days, depending on the cultivar. Reduce watering to once a week when rain is insufficient. Sunflowers require 1 inch of rain a week. During dry spells, supplemental watering may be necessary.

Control weeds by cutting them at the ground level with a hoe, or mulch with a 2-inch layer of grass clippings or other organic mulch.