About
Delphinium 'Marathon' is a stately named delphinium cultivar producing tall, sturdy stems with deeply cut, palmate foliage and a magnificent spike densely packed with spurred, semi-double flowers in early summer. A border showstopper for a sunny, sheltered garden position.
About the genus
Delphinium, the larkspurs and delphiniums, are annuals, biennials and perennials with palmately lobed basal leaves and tall spikes, racemes or panicles of showy, spurred flowers in shades of blue, purple, pink, white or yellow in early summer. Among the most dramatic of all border perennials.
Plant details
Suggested usesBack of borders, cottage gardens, cutting gardens. Superb cut flowers.
Care notes
CultivationFertile, well-drained soil in full sun with shelter from wind. Stake tall varieties. Mulch in spring.
PruningCut spent spikes to a lateral after first flowering to encourage a second flush in late summer.
PropagationTake basal cuttings in spring. Sow seed in late winter (some need cold stratification).
Pest resistanceSlugs and snails are the main threat, especially to young growth in spring. Caterpillars may eat leaves.
Disease resistancePowdery mildew, black spot, and crown rot in wet soils. Good air circulation essential.