Overview
Helianthus tomentosus is a perennial in the genus Helianthus, part of the Asteraceae family. Helianthus tomentosus grows best in full sun, and tolerates well-drained and sandy or loamy soils and 6.0-7.5 pH. Its UK hardiness is rated H7. Suggested uses include edible tubers and ornamental. It is native to central North America.
About
Helianthus tomentosus is a perennial sunflower grown for its edible tubers and late-summer flowerheads. Native to central North America, it suits full-sun sites on well-drained sandy or loamy soil with a pH of 6.0–7.5. It prefers moist, well-drained conditions and is fully hardy in the UK (H7). It flowers from July to October.
Wikipedia contributors, CC BY-SA 4.0 — Jerusalem artichoke
About the genus
Helianthus is a genus comprising around 50 species of annual and perennial flowering plants in the daisy family Asteraceae commonly known as sunflowers. The species of Helianthus are native to North America. The best-known species is the common sunflower.
Wikipedia contributors, "Helianthus", CC BY-SA 4.0 — Helianthus
In the garden
Helianthus tomentosus belongs to the Asteraceae and originates from central North America. Gardeners grow it both for its edible tubers and as an ornamental sunflower; the combination makes it useful where a productive crop and summer floral display are wanted. Plant in an unshaded position with freely draining sandy or loamy soil and a neutral to slightly acidic pH (6.0–7.5). Maintain soil that is moist but not waterlogged; the species favours conditions described as moist, well-drained. As a fully hardy (H7) perennial, it tolerates UK winters across the country and reliably returns in spring. The flowering season runs from July to October, providing late-summer interest. Use Helianthus tomentosus at the rear of a mixed border to carry height and flower through late summer, or allocate part of a vegetable plot for tuber production where the soil matches its drainage and pH preferences. Because it serves both ornamental and edible purposes, plan spacing and placement to allow room for a harvest as well as for the flowerheads to be seen from paths or seating areas. Expect a harvestable crop of tubers alongside the July–October floral display.
Growing conditions
Best soil and position for Helianthus
- Sunlight
- full sun
- Soil type
- well-drained, sandy or loamy
- Soil pH
- 6.0-7.5
- Soil moisture
- moist, well-drained
- UK hardiness
- H7
Plant details
Helianthus tomentosus size, habit and characteristics
- Plant type
- perennial
- Suggested uses
- edible tubers, ornamental
- Native to
- central North America
Care notes
Pruning and caring for Helianthus tomentosus
- Cultivation
- Plant tubers in spring, 10-15 cm deep, spaced 30-45 cm apart; tolerate poor soils; drought resistant once established
- Pruning
- Cut back to ground level after flowering or in late autumn
- Propagation
- tuber division
Frequently asked questions
How do I grow Helianthus tomentosus?
Plant tubers in spring, 10-15 cm deep, spaced 30-45 cm apart; tolerate poor soils; drought resistant once established.
Where is the best place to plant Helianthus tomentosus?
Helianthus tomentosus prefers full sun.
What soil does Helianthus tomentosus need?
Helianthus tomentosus grows best in well-drained and sandy or loamy soil. It prefers 6.0-7.5 soil. Aim for soil that stays moist to well-drained.
How do I prune Helianthus tomentosus?
Cut back to ground level after flowering or in late autumn.
Is Helianthus tomentosus hardy in the UK?
Helianthus tomentosus has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.
How do I propagate Helianthus tomentosus?
Tuber division.
More in the Helianthus genus
- Helianthus 'Carine'Sunflower
- Helianthus annuus Solano Orange Nr. 14 (Solano Series)Common Sunflower
- Helianthus orygalis
- Helianthus scaberrimusSunflower