Helenium autumnale. Its native range extends from Northwest Territories to California and Florida. As a garden perennial it is an easy and dependable late summer bloomer, and an important food source for end-of-the-season pollinators such as bumble bees preparing for over wintering. Autumn Sneezeweed seeds produce plants that grow to 130cm (51") tall, each bearing as many as 100 bright yellow flowers in a branched array. Keep spent flowers picked, and don't let the soil dry out completely during the growing season. Helenium looks sensational mixed with the shocking red flowers of Crocosmia. Support unruly stems with twigs stuck into the soil, or with flower support netting.
This dependable perennial blooms from late summer into fall with numerous bright yellow pin-cushion flowers atop tall stems. It looks superb in mass plantings, or planted between clumps of Crocosmia. Continue reading below for tips on how to grow Helenium from seed.
Season & Zone
Exposure: Full sun
Zone: Hardy to Zone 3
Sow in doors 8-10 weeks before planting out in early spring when the soil is cool and light frost is still possible. Or direct sow in early spring or early autumn. The ideal temperature for germination is 21°C (70°F). Seeds will sprout in 7-10 days.
Barely cover the seeds with soil. Transplant or thin to stand 60-90cm (24-36″) apart.
Stake these tall growing plants in windy gardens. Ordinary, well-drained soil will do, but Helenium prefers rich soil at a pH of 5.5 to 7.0. Don’t let the soil dry out completely during the growing season, and deadhead regularly once flowering begins. Divide clumps every three to four years to maintain vigour. Division works best in the spring north of Zone 7, and in the fall in southern climes.