About
Iris forrestii, the Forrest iris, is a clump-forming herbaceous perennial to 45 cm with narrow, glossy-above, greyish-beneath leaves and elegant yellow flowers to 6 cm across, the falls finely streaked with brown lines, in early summer. A graceful and ornamental Siberian iris for a moist, partly shaded border.
About the genus
Iris, the irises, are rhizomatous or bulbous perennials producing narrow, often sword-shaped leaves and distinctive flowers with three large, spreading or pendent fall petals alternating with three erect standard petals. They flower from late winter to early summer in every colour of the rainbow.
Growing conditions
SunlightFull sun, Partial shade
Soil typeClay, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureMoist but well-drained, Well-drained
AspectSouth-facing, West-facing, East-facing
ExposureExposed, Sheltered
UK hardinessH6
Plant details
Plant typeHerbaceous Perennial
HabitBushy
FoliageDeciduous
Height0.1-0.5 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCity and courtyard gardens, Coastal, Cottage and informal garden
Native toSW China
ToxicityHarmful if eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Care notes
CultivationGrow in moisture-retentive, well-drained soil in full sun or part shade; mulch in spring with well-rotted organic matter particularly in drier soils
PruningRemove any dying foliage in autumn, old flower stems can be cut down after flowering
PropagationPropagate by seed in autumn or spring, propagate by division in summer or autumn
Pest resistanceMay be susceptible to slugs, snails and thrips
Disease resistanceMay be susceptible to aphid-borne viruses, bacterial soft rot and grey moulds; see Iris diseases