Planting Sunflowers Written by admin on August 19, 2016. Posted in Flowers, Sunflowers Ground Temp: 55-60°F PH level: 6.0-7.5 Spacing: 30 inches apart for rows, 6″ spacing Depth: 1″ Time to Bloom: Sprouts in 7-10 days, bloom in 60-90 days Notes: Plant in succession every 2-3 weeks. Continue Reading