Allocasuarina duncanii

RHS Plant Profile

Duncan's she-oak

Trees Shrubs

A dioecious plant which needs both sexes to bear fruit. The roots are nitrogen-fixing and also, able to bind loose sandy soils for stabiliasation purposes.

Position

Full sun

Soil Types

Loam, Sand

Max Height

2.5-4 metres

Max Spread

1.5-2.5 metres

Size

Time to Maturity: 10–20 years
Max Spread: 1.5-2.5 metres
Max Height: 2.5-4 metres

Growing Conditions

Loam Sand

Moisture: Well–drained
pH: Acid or Alkaline or Neutral

Position

Full sun

Aspect: East–facing or North–facing or South–facing or West–facing
Exposure: Exposed or 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
Drought Resistance: Yes

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Casuarinaceae
Native to GB/Ireland: No
Foliage: Evergreen
Habit: Columnar upright
Genus
Name Status: Correct

How to Grow

Cultivation

General appearance of a conifer, with 'needle-like' branches resembling leaves. Female plants have small, fluffy red flowers which become - if a male plant is also grown - interesting decorative 'cone-like' woody fruits.

Suggested planting locations and garden types

Prairie planting
Coastal
Banks and slopes

Pruning

pruning group 1

Pests

Generally pest-free

Diseases

Generally disease free