Magnolia acuminata 'Blue Opal'

RHS Plant Profile

cucumber tree 'Blue Opal'

Trees

Buy this from Plant Nurseries
7 Suppliers

Deciduous, upright tree about 15-20m tall or more, with elliptic, green leaves to 25cm long. In late spring producing striking, blue-green flower buds that mature to dark yellow flowers with dark blue-green outer petals, the flowers appear at the same time as foliage

Position

Full sun, Partial shade

Soil Types

Clay, Loam, Sand

Max Height

Higher than 12 metres

Max Spread

wider than 8 metres

Size

Time to Maturity: 20–50 years
Max Spread: wider than 8 metres
Max Height: Higher than 12 metres

Growing Conditions

Clay Loam Sand

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

Position

Full sun Partial shade

Aspect: West–facing or South–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): H6

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Magnoliaceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Columnar upright, Bushy
Genus: Magnolia can be deciduous or evergreen trees or shrubs, with large, showy, often fragrant flowers, often opening before the leaves, and sometimes followed by colourful cone-like fruit
Name Status: Accepted

How to Grow

Cultivation

Prefers moist, but well drained, neutral to acid soil, but it is tolerant of chalky soils. Mulch in spring to keep the soil moist if gardening on dryer soil. Plant in full sun or light shade with shelter from cold winds. Later frost may cause damage the flowers and foliage. For more information see magnolia cultivation advice

Propagation

Propagate by taking semi-ripe cuttings or softwood cuttings

Suggested planting locations and garden types

Architectural
Cottage and informal garden

Pruning

Pruning Group 1. See magnolia pruning

Pests

May be susceptible to scale insects, horse chestnut scale and capsid bug

Diseases

May be susceptible to coral spot, phytophthora, grey moulds, honey fungus, a virus or fungal leaf spot