Grow safflower plants in areas where the annual rainfall does not exceed 15 inches per year and there are at least 120 frost-free days in the growing season. Choose a permanent location to plant the seeds 1 1/2 inches deep in rows that are 6 to 8 inches apart. Wait to plant the seeds until the soil temperature reaches 40 degrees Fahrenheit. The seedlings appear about three to four weeks after planting.
Prepare the beds for planting by testing the soil. Add high nitrogen and phosphorous fertilizer if the test shows the soil is lacking. The plants prefer rich, well-drained soil. Mix the soil and any amendments you add for growing the flowers
Safflower plants grow approximately 3 feet above ground and develop 8 to 10-foot tap roots. Their leaves develop sharp spines, so plant them away from foot traffic. Safflowers make good dried flowers. Collect the flowers after the buds begin to open. If growing safflower for attracting birds, do not harvest the flowers but leave them in place.
Harvest safflower seeds about a month after the flowering stops. Wear gloves and heavy clothing as protection when gathering seeds. Crush the dried flowers to collect approximately 15 to 20 seeds per flower.