Description

Sunflowers are grown from seeds directly sown in the garden after the danger of frost has passed.

– Directly sow seeds in average soil in full sun after all frost risk has passed.
– When selecting a site, ensure sunflowers have well-drained soil and are positioned in an open area of the garden since they face the sun. Taller varieties should be planted at the northern end of the garden to prevent shading of other plants.
– Prepare the soil by removing weeds and incorporating organic matter into the top 6-8 inches; then level and smooth the soil.
– Most plants benefit from organic matter in the soil. Compost is an excellent source due to its balanced nutrients and ideal pH level. If compost isn’t available, apply 1-2 inches of organic mulch after planting, which will decompose into compost over time. After the growing season, a soil test will indicate necessary soil amendments for the next season.
– Plant seeds ½ inch deep in groups of 2 or 3 seeds, spacing groups 18-24 inches apart based on the variety.
– Lightly firm the soil, water thoroughly, and keep evenly moist.
– Seedlings typically emerge in 7-10 days.
– Thin to one plant per group when seedlings have two sets of leaves.
– Manage weeds throughout the growing season, as they compete with plants for water, space, and nutrients. Cultivate often or use mulch to prevent weed seed germination. Mulching also helps retain soil moisture and regulate soil temperature.
– For annuals, shredded leaf mulch provides a natural appearance and improves soil as it decomposes. Keep mulch away from plant stems to prevent potential rot.
– Maintain even soil moisture, avoiding waterlogging.
– Established sunflowers can tolerate drought conditions.
– Fertilization is unnecessary unless the soil is poor; avoid over-fertilizing.
– Monitor for pests and diseases; consult your local Cooperative Extension Service for recommended pest controls.
– Some varieties produce a single bloom, after which the plant may be removed once the bloom fades.
– Remove plants after frost kills them in the fall to prevent disease issues in the following year.
– Edible sunflowers mature approximately 3 months after sowing. To harvest seeds, cut heads off after stalks dry but before fall or winter rains. Check maturity by observing center florets shriveling, the back of the flower head turning yellow, or the head starting to droop. Hang heads in a warm, well-ventilated area to fully ripen and dry seeds. Protect seeds with cheesecloth, netting, or a ventilated paper bag to collect any that may drop during drying.
– Shorter varieties are suitable for containers; use commercial potting mix for optimal growth.
– Pollenless varieties are excellent choices for cut flowers.