Iris 'White Knight' (TB)
A rhizomatous perennial, to around 60cm high in flower, with upright, sword-shaped, grey-green leaves. Flowers are white, sometimes with light veining on the falls, and lightly scented. Late season
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Size
Ultimate height
0.5–1 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drained, Well–drainedpH
Acid, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | White | Green Grey Silver | ||
|---|---|---|---|---|
| Summer | White | Green Grey Silver | ||
| Autumn | ||||
| Winter |
Position
- Full sun
Aspect
South–facing
Exposure
Sheltered Hardiness
H7Botanical details
- Family
- Iridaceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Clump forming
- Potentially harmful
- Harmful 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
- Genus
Iris may be rhizomatous or bulbous perennials, with narrow leaves and erect stems bearing flowers with 3 large spreading or pendent fall petals, alternating with 3 erect, often smaller, standard petals, in late winter, spring or early summer
- Name status
Accepted
- Horticultural Group
- Tall Bearded irises are herbaceous rhizomatous perennials to 70cm or more, with flowers 10-20cm across, bearded on the falls, in late spring and early summer
How to grow
Cultivation
Thrives in a sunny position, in neutral to slightly acid soil with good drainage. Plant rhizomes just above soil level, as sun on the rhizomes encourages flowering. See bearded iris cultivation
Propagation
Propagate by division, see dividing irises
Suggested planting locations and garden types
- City and courtyard gardens
- Cottage and informal garden
- Flower borders and beds
- Wall side borders
Pruning
Remove spent flower stems in summer, and any dying foliage in autumn
Pests
Diseases
May be susceptible to leaf spots, rust diseases, rhizome rot and viruses; see Iris diseases for more details
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The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.