For best results, sunflowers require well-draining soil with plenty of organic matter. Ensure the soil is neither too wet nor too dry and has a pH of 6-7.5. Dig in some compost to improve water retention and add fertility. Firm it down before planting and remove any clumps or weeds.
For container plants, opt for a potting mix that contains perlite or vermiculite for good drainage and organic matter such as peat moss, compost, or humus for added nutrient levels.
Sunflowers thrive in warmer temperatures, so they use mulch or straw to insulate the root zone in cooler climates and extend the growing season. Water regularly but don’t overwater; irrigate once or twice weekly during extended dry periods, aiming to keep the soil evenly moist without saturating it. Feed monthly with a balanced liquid fertilizer such as 8-8-8 fertilizer throughout the entire growing season for bigger blooms and more flowers.