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Perennial Sunflower
Helianthus
Perennial Sunflower blooms from August through October.
This entry comes from our curated library and has not yet been independently checked against outside sources. Curated is not unreliable: a standing audit keeps every entry internally consistent, and the source-by-source check is working through the whole library in the open.
Growing Perennial Sunflower
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 4–9. Expect it to reach about 4.9 ft tall and 2.6 ft wide at maturity, in roughly 2 years.
When to plant Perennial Sunflower
Plant Perennial Sunflower in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. For the middle of its hardy zones 4 to 9 range, spring means March to May and fall means August or September. Once settled, it blooms from August to October.
Month-by-month timing for your zone is on the planting calendar: for the middle of its range, start with zone 6 in March.
Good to know about Perennial Sunflower
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Worth knowing
Flopping and staking are one problem with two fixes. Cut tall stems back by up to half before mid-July and they grow shorter, sturdier, no stake needed. per NC State and Penn State
Spreads aggressively by rhizomes
Many spread by creeping rhizomes into large colonies. Jerusalem artichoke is worst: it re-sprouts from any tuber or root fragment left behind, so give it a barrier. per NC State
Feeds pollinators and birds
Late-season nectar and pollen feed bees, butterflies and specialized native bees; it hosts Silvery Checkerspot caterpillars, and the seeds feed birds into fall. per NC State
Prone to powdery mildew
Powdery mildew is common, worst on Jerusalem artichoke and swamp sunflower. Full sun, good spacing, and the early-summer cut-back for airflow keep it down. per NC State
Jerusalem artichoke is edible
Jerusalem artichoke, the tuberous one, grows edible tubers eaten raw or cooked, with a nutty flavor. They store carbohydrate as inulin, not starch. per NC State
What pairs well with Perennial Sunflower
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Thyme
Shares full sun and low to moderate water; blooms in late spring, before this one opens; low at 6 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
English Daisy
Shares full sun and moderate water; blooms in mid spring, before this one opens; low at 6 in, to carpet the ground beneath; both offer pollinator forage, in different months.
Lobelia
Takes full sun to part sun and moderate water; opens in late spring and overlaps into this one's season; low at 8 in, to carpet the ground beneath; both are strong pollinator plants.
Tulip Tree
Shares full sun and moderate water; blooms in late spring, before this one opens; both are strong pollinator plants, and they feed in different months; both are native plants.
Creeping Phlox
Shares full sun and low to moderate water; blooms in mid spring, before this one opens; low at 6 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
Pansy
Takes full sun to part sun and moderate water; blooms in early spring, before this one opens; low at 8 in, to carpet the ground beneath; both offer pollinator forage, in different months.
Hyacinth
Shares full sun and moderate water; blooms in early spring, before this one opens; lower at 10 in, for the front of the border; both offer pollinator forage, in different months.
Sweet Alyssum
Shares full sun and moderate water; low at 5 in, to carpet the ground beneath; opens in late spring and overlaps into this one's season; both are strong pollinator plants.
Try Perennial Sunflower with its top companions in a garden →
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