Description

Growing Tips for Sunflowers:

Sunflowers are best grown from seeds planted directly in the garden after the threat of frost has passed.

Here are some guidelines for successful growth:

• Directly sow seeds in average soil in full sun once all frost danger has subsided.
• Choose a well-drained site in your garden as sunflowers face the sun and need an open area. Taller varieties should be planted at the north end of your garden to avoid shading other plants.
• Prepare the soil by removing weeds and incorporating organic matter into the top 6-8 inches of soil. Level and smooth the soil surface afterward.
• Organic matter such as compost enriches the soil with essential nutrients and maintains an ideal pH level. If compost isn’t available, apply 1-2 inches of organic mulch after planting; it will gradually decompose into compost. Conduct a soil test after the growing season to determine necessary amendments for the next year.
• Sow seeds ½ inch deep in groups of 2-3 seeds, spacing groups 18-24 inches apart depending on the variety.
• Lightly firm the soil after planting, then water evenly to keep it consistently moist.
• Seedlings typically emerge within 7-10 days. Once seedlings have developed two sets of leaves, thin to one plant per group.
• Control weeds throughout the growing season; weeds compete with sunflowers for water, nutrients, and space. Cultivate frequently or apply mulch to prevent weed seeds from germinating.
• Mulches also help retain soil moisture and maintain consistent soil temperatures. Use organic mulches like shredded leaves for a natural look; ensure mulch does not touch plant stems to prevent potential rot.
• Keep soil evenly moist but avoid waterlogging.
• Established sunflowers can endure drought conditions.
• Unless soil quality is poor, sunflowers generally do not require additional fertilizer. Avoid over-fertilization.
• Monitor for pests and diseases; consult your local Cooperative Extension Service for recommended pest controls.
• Some sunflower varieties produce only one bloom; remove spent blooms promptly to prolong flowering. After frost kills plants in fall, remove them to prevent disease issues the following year.
• Edible sunflowers mature in about 3 months after sowing. Harvest seeds by cutting heads after stalks are dry but before fall or winter rains. Check for maturity by examining florets in the flower disk; mature seeds have shriveled florets and yellowing backs. Hang heads in a warm, well-ventilated area to ripen fully. Protect seeds and collect those that fall with cheesecloth, netting, or a paper bag with ventilation holes.
• Shorter sunflower varieties are suitable for container gardening; use commercial potting mix for containers.
• Pollenless varieties are excellent choices for cut flowers.