Common sunflowers Helianthus annuus are fast-growing warm weather annuals. These native North Americans have remarkable tolerance for hot, dry growing conditions and deliver maximum beauty with minimum effort on your part. Known for their generous seed production, each sunflower bloom may contain up to 2, seeds, which are among the easiest to collect and save. Unlike hybrids, heirloom varieties grow true to seed and are the best types to harvest for replanting.
Sunflowers: How to Plant, Grow, and Care for Sunflower Plants | The Old Farmer's Almanac
False sunflowers Heliopsis helianthoides , sometimes called oxeye sunflowers, produce sunflower-like blooms throughout the summer. Hardy in U. Department of Agriculture plant hardiness zones 3 through 9, false sunflowers grow best in full to partial sunlight and loamy moist soils. They will grow in poor rocky soils and tolerate drought. False sunflowers grow in clumps that increase in size each year.
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Native to North America, sunflowers are heat-tolerant, resistant to pests, and simply beautiful. You can even harvest their edible seeds. Tall and coarse, the plants have creeping or tuberous roots and large, bristly leaves.