About
Helianthus 'Triomphe de Gand' is a tall perennial sunflower to around 125 cm with dark-green leaves. Bright-yellow flowers with yellow centres appear from late summer to autumn � a good choice for bringing colour to the back of a border late in the season.
About the genus
Helianthus, the sunflowers, are tall, erect annuals and tuberous or rhizomatous perennials with coarse, simple, rough-textured leaves and large, showy, daisy-like flowerheads in yellow, orange or occasionally red tones. Excellent for the back of a sunny border and important plants for pollinators.
Growing conditions
SunlightFull sun
Soil typeChalk, Clay, Loam
Soil pHAcid, Alkaline, Neutral
Soil moistureMoist but well-drained
AspectEast-facing, South-facing, West-facing
ExposureSheltered
UK hardinessH2
Plant details
Plant typeAnnual Biennial
HabitBushy, Clump forming
FoliageDeciduous
Height1-1.5 metres
Spread0.5-1 metres
Time to full height1-2 years
Suggested usesCottage and informal garden, City and courtyard gardens, Wildlife gardens
Care notes
CultivationGrow in moderately fertile, neutral to alkaline, humus-rich, moist but well-drained soil in full sun
PruningCut back to the ground in autumn or leave for birds to eat the seeds
PropagationPropagate by seed (sown indoors) between April and May and keep in a sunny location, planting out in late spring or early summer when the risk of frost has passed. Also propagate by seed (sown outdoors) when the risk of frost has passed
Pest resistanceMay be susceptible to slugs and snails
Disease resistanceMay be susceptible to powdery mildews and sclerotinia diseases