About
Monarch' is a herbaceous perennial making a clump to 2.5m tall, with lance-shaped or ovate leaves to 30cm long and semi-double, dark-centred, rich yellow flower-heads 10-15cm wide from late summer through early autumn.
About the genus
Helianthus can be tall, erect annuals, tuberous or rhizomatous perennials, with coarse simple leaves and large daisy-like flower-heads
Growing conditions
SunlightFull sun
Soil typeChalk, Clay, Loam
Soil pHAlkaline, Neutral
Soil moistureMoist but well-drained
AspectWest-facing, South-facing, East-facing
ExposureSheltered
UK hardinessH5
Plant details
Plant typeHerbaceous Perennial
HabitColumnar upright
FoliageDeciduous
Height2.5-4 metres
Spread0.5-1 metres
Time to full height2-5 years
Suggested usesCottage and informal garden, City and courtyard gardens, Coastal
Care notes
CultivationGrow in a moderately fertile, humus-rich, moist but well-drained, neutral to alkaline soil in full sun. Will flower best after a long hot summer. May need support
PruningCut back after flowering
PropagationPropagate by seed or division. Divide established clumps every 2-4 years to both increase plants and retain vigour. See sowing seeds indoors for further advice
Pest resistanceMay be susceptible to slugs and snails
Disease resistanceMay be susceptible to powdery mildews and sclerotinia diseases