Begonia 'Black Knight' (R)
begonia 'Black Knight'
A rhizomatous tender, evergreen perennial, 35cm high, with large, obliquely heart-shaped, deep burgundy leaves, whose shape is emphasised by a zone near the margin of pale pink and white speckles, and pink flowers from late summer to autumn
Size
Ultimate height
0.1–0.5 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 | Red Pink White | |||
|---|---|---|---|---|
| Summer | Pink | Red Pink White | ||
| Autumn | Pink | Red Pink White | ||
| Winter | Red Pink White |
Position
- Partial shade
Aspect
West–facing or East–facing or North–facing or South–facing
Exposure
Sheltered Hardiness
H1BBotanical details
- Family
- Begoniaceae
- Native to GB / Ireland
- No
- Foliage
- Evergreen
- Habit
- Bushy
- Potentially harmful
- Ornamental bulbs - not to be eaten. Wear gloves and other protective equipment when handling. Pets: Ornamental bulbs - not to be eaten - see the HTA guide to potentially harmful plants for further information and useful contact numbers
- Genus
Begonia can be annuals, evergreen or deciduous perennials or shrubs, with fibrous, tuberous or rhizomatous roots and usually asymmetrical leaves, often strikingly patterned, and small or large flowers, both male and female in the same cluster
- Name status
Accepted
- Horticultural Group
- Rex begonias are evergreen, rhizomatous perennials grown for their handsome, brightly coloured leaves, rather than the small pale pink or white flowers which may appear in spring, summer or autumn
How to grow
Cultivation
Grow in light, open, very well-drained, neutral to slightly acidic, peat-free potting compost, and in bright indirect light, at an optimum temperature of 19-23ºC; water moderately when in growth, with balanced liquid fertilizer at alternate waterings; lift tubers in autumn, dry off, and store, then plant again in spring; for more advice, see begonia cultivation (outdoor)
Propagation
Propagate by root cuttings of rhizome sections in summer, or by leaf cuttings in spring or summer in a propagating case, in partial shade
Suggested planting locations and garden types
- Houseplants
- Patio and container plants
Pruning
No pruning required
Pests
May be susceptible to caterpillars, mealy bugs, mites, glasshouse thrips, vine weevil and aphids
Diseases
May be susceptible to grey moulds (Botrytis), powdery mildews, stem rot, and rhizome rot
Get involved
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.