About
Geranium maderense, giant herb robert, is a strong but short-lived evergreen perennial or biennial to 1.5 m from Madeira, forming a bold rosette of deeply dissected, finely cut, bright-green leaves to 20 cm on red-flushed stalks. In summer, a massive branching panicle to 1.5 m tall carries large numbers of purplish-pink, 4 cm flowers with darker centres. A spectacular architectural plant for a sheltered, frost-free garden or large conservatory.
About the genus
Geranium, the cranesbills, are annuals, biennials and herbaceous or evergreen perennials with rounded, usually palmately lobed or divided leaves and loose clusters of rounded, five-petalled flowers in white, pink, purple or blue. Among the most versatile and garden-worthy of all perennial genera.
Growing conditions
SunlightFull shade, Full sun, Partial shade
Soil typeChalk, Clay, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureWell-drained
AspectEast-facing, South-facing, North-facing, West-facing
ExposureExposed, Sheltered
UK hardinessH3
Plant details
Plant typeHerbaceous Perennial, Conservatory Greenhouse
HabitTufted
FoliageEvergreen
Height1-1.5 metres
Spread0.5-1 metres
Time to full height1-2 years
Suggested usesCottage and informal garden, Mediterranean climate plants, City and courtyard gardens, Coastal, Wildlife gardens
Native toMadeira
Care notes
CultivationGrow outdoors in well-drained soil in either sun or shade in frost-free area. Grow under glass in peat-free, loam-based compost with added sharp sand in bright filtered light. Remove flowered stems and old leaves to encourage the production of new leaves and flowers
PruningNo pruning required
PropagationPropagate by seed, division or take basal cuttings
Pest resistanceGenerally pest-free
Disease resistanceMay be susceptible to downy mildews and powdery mildews