How Deep Should Sunflower Seeds Be Planted?

Recommendations

• Plant seeds 1 inch deep and no closer than 6 inches apart after the last danger of frost has passed. Thin to a separation distance of 1 1/2 feet after seedlings appear.

Variations

• Experts at the Universities of Wisconsin and Minnesota recommend a planting depth range from 1 to 3 1/2 inches. They suggest going shallower than 1 inch in silt loam and clay soils, where crusting or packing may occur.

Transplanting

• If starting indoors, use peat pots, which can be planted whole into the ground. (Sunflowers do not tolerate transplanting very well.) Plan on keeping them indoors for a week at most; a longer indoor period can result in weak stems and stunted tap roots.

Pregermination

• To make the most of planting season, plant only viable, successfully germinating seeds. A week or two before you intend to plant outside, place seeds between two paper towels that have been dampened but not soaked. After two days, begin checking for germination daily for two weeks. Seeds that have sprouted are ready to plant.

Location

• Choose a location that receives at least six to eight hours of sun per day. Remember how big sunflowers can get; don't plant them where they will shade smaller plants.