Cupressocyparis x leylandii (Leyland Cypress)


Michael's Opinion

Leyland cypress is an extremely vigorous, drought tolerant plant. This hybrid will outgrow its site if left unpruned and may causes disputes in smaller residential areas where it has overgrown its boundaries. Leyland cypress is highly valued in commercial settings such as parking lots as it is quite urban tolerant.

Botanical Information

FamilyCupressaceae
GenusCupressocyparis
Speciesx leylandii
Synonymsx Cupressocyparis leylandii, Callitropsis × leylandii
CategoryWoody
TypeTree (evergreen)
OriginJohn Naylor was given the Leighton Hall estate by his uncle Christopher Leyland. Several plants, including C. nottkatensis, and C. macrocarpa were planted on the estate, with C. macrocarpa pollinating C. nootkatensis the resulting cross produced Cupressocyparis x leylandii
Pronunciation

Details

USDA Hardiness Zone6b - 7a
USDA Hardiness Ref.
Canadian Hardiness Zone6b
Canada Hardiness Ref.
RHS Hardiness ZoneH6
RHS Hardiness Ref.
Temperature (°C)-20 to -15
Temperature (°F)4 -5
Height30 m
Spread5-7 m
GrowthFast
Flowering PeriodSeptember

Description and Growing Information

General DescriptionA fast-growing hybrid widely used in many landscape applications. The plant is sterile and can only be propagated from cuttings. It forms a columnar to pyramidal shaped tree with dark green bluish scales.
ID CharacteristicOpposite forming, bluish-green scales form distinctive long ascending branches. It has a classic Christmas tree form, with distinctive round black cones that are sharp on the edges.
ShapeForms a loosely compact, pyramidal, somewhat columnar shape but looses form when not pruned.
LandscapeLeyland cypress exhibits significantly fast and vigorous growth, even when provided with poor site conditions, making it a good screen, windbreak, and green border tree. It can also be utilized to compensate for the time needed for slower growing plants to reach an aesthetically pleasing size. Also very popular in the urban environment as it is salt tolerant.
PropagationEasily propagates from softwood cuttings. Seeds are rarely produced with those found being generally infertile. Take cuttings from plants 5 years old and no older than 15 years in late May to early August through September from semi-ripe wood. Cuttings also benefit from misting and maintaining a high humid environment (78 %) and bottom heat, as well as wounding and treatment with a rooting hormone.
CultivationIt retains the vigorous growth rate of C. nootkatensis, and poor site tolerances of its other parent, C. macrocarpa. It can tolerate a wide range of conditions including salt, pollution and compaction and does well when planted in a temperate, moist environment. The tree prefers a slightly acidic, semi-clay soil, and can still thrive if even if it is not well drained.
PestsSusceptible to honey fungus and Cercosporidium blight, and Ceridium canker
HabitatHorticultural origin.
Bark/Stem DescriptionDark brown with slight purple/red tinges and is very thin and week.
Flower/Leaf Bud DescriptionTiny shoots produced at the end of a scale, averaging 1-3 mm, and emerging a dull yellow.
Leaf DescriptionOlder leaves are dark green with a blue tinge while young leaves are light green with a slight yellow tinge. The leaves are scale-like and grow to be 3-8 mm in length without pronounced venation: the leaves are alternate and opposite
Flower DescriptionSmall, dull and yellow in colour.
Fruit DescriptionSmall male globose cones, usually 8 mm in diameter and brownish black in colour with sharp edges but does not produce viable seed.
Colour DescriptionDark green with a blue tinge but light bright green when younger. The bark is a brownish purple colour.
Texture DescriptionFine, somewhat smooth and leathery.

Photographs