What Soil Is Best for Growing Sunflower Seeds?

Soil Type

• Sunflowers will thrive in a wide range of soil types. You can plant in sandy soil or in clay and have reasonable expectations of success either way.

Soil Preparation

• According to Brenda Hyde's article "Anyone Can Grow Sunflowers!", the best choice is a "well-drained soil with peat added." Hyde recommends digging a bag of peat into the soil before you plant. The National Gardening Association suggests something similar: dig a small hole for each plant and fill the hole with high-quality potting soil.

Drainage

• Though sunflowers are not especially intolerant of flood situations, they do prefer a well-drained environment. Don't plant them in wet, swampy soils, and make sure any planting containers have adequate drainage.

Macronutrients

• Sunflowers require medium to high levels of nitrogen in the soil, as they are somewhat inefficient users of that macronutrient. Because sunflowers tend to drain soils of their nutrient resources, the Thomas Jefferson Agricultural Institute recommends against planting sunflowers in the same field more frequently than once every three to four years. If you grow sunflowers in the same spot every year, you will need to enhance the soil with compost or fertilizer each time you plant. The National Gardening Association recommends mixing a time-release fertilizer into your planting medium.

Salt Content

• Sunflowers, even more than most plants, dislike a saline environment. According to the Alternative Field Crops Manual housed at Purdue University's website, sunflowers are rated as having low salt tolerance. By contrast, corn and wheat are rated medium and sugar beets are rated high.