Chrysanthemum 'Royal Knight' (22c) | chrysanthemum 'Royal Knight'

RHS 1996

Synonyms

Dendranthema 'Royal Knight'

Bedding Conservatory Greenhouse Herbaceous Perennial

'Royal Knight' is a half-hardy perennial to 65cm in height, with deep maroon flowers 7.5cm across, the florets dusky light purple on the reverse

Position

Full sun

Soil Types

Chalk, Clay, Loam, Sand

Max Height

0.5-1 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 1–2 years
Max Spread: 0.1-0.5 metres
Max Height: 0.5-1 metres

Growing Conditions

Chalk Clay Loam Sand

Moisture: Moist but well–drained or Well–drained
pH: Acid or Alkaline or Neutral

Position

Full sun

Aspect: South–facing or West–facing or East–facing
Exposure: Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): H3

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Asteraceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Bushy
Potentially harmful: Skin allergen. Wear gloves and other protective equipment when handling
Genus: Chrysanthemum are erect woody-based perennials with aromatic, pinnately lobed leaves and flowerheads of diverse form, from late summer to late autumn
Name Status: Accepted
Horticultural Group

Horticultural Classification Codes

Horticultural Classification Codes are often given to genera which have a large number of species or cultivars. They are used to categorise cultivated plants based on specific, shared characteristics such as shape, colour, size or flowering time, and can be displayed as letters or numbers

For example:
Dahlia ‘Sunset Kate (Sin) = Single flower
Rosa ‘Marigold’ (HT) = Hybrid Tea: Reflexed Charm chrysanthemums are compact plants with many small, double flower-heads with overlapping, recurved ray-florets, flowering in autumn

How to Grow

Cultivation

Grow in a cold frame in a peat-free, loam-based potting compost and move into a warm glasshouse in early autumn. Provide bright filtered light with good ventilation and a minimum temperature of 10°C. During the growing season water moderately and apply a balanced liquid fertiliser weekly

Propagation

Propagate by rooting softwood cuttings in peat-free potting compost at 16°C in spring. Pot on rooted cuttings in late June to early July into 23cm pots and pinch out as soon as established

Suggested planting locations and garden types

Patio and container plants

Pruning

Pinch out growing tips and disbud as required

Pests

Susceptible to leaf and bud eelworms, aphids, glasshouse whitefly, glasshouse red spider mite and capsid bug

Diseases

May be susceptible to glasshouse grey mould, powdery mildews and chrysanthemum white rust