Acer palmatum 'Ornatum' (Japanese maple 'Ornatum')

Botanical name

Acer palmatum 'Ornatum'

Other names

Japanese maple 'Ornatum', Acer palmatum 'Dissectum Ornatum'

Genus

Acer Acer

Variety or Cultivar

'Ornatum' _ 'Ornatum' is a compact, rounded, slow-growing, deciduous tree with finely divided, mid-green leaves, bronze-red when young and turning crimson in autumn. Clusters of reddish-purple in spring are followed by winged, reddish-purple fruit.

Native to

Garden origin

Foliage

Deciduous

Habit

Compact, Rounded

Awards

RHS AGM (Award of Garden Merit)

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Colour

Flower

Red, Insignificant or absent, Purple in Summer

Foliage

Green, Flushed red in Spring; Green, Flushed red in Summer; Yellow in Autumn

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How to care

Watch out for

Specific pests

Horse chestnut scale , Aphids

Specific diseases

Tar spot , Honey fungus , Verticillium wilt

General care

Propagation methods

Grafting, Softwood cuttings

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Monthly care advice

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Where to grow

Acer palmatum 'Ornatum' (Japanese maple 'Ornatum') will reach a height of 4m and a spread of 4m after 20-30 years.

Suggested uses

Architectural, Beds and borders, City, Containers, Cottage/Informal, Low Maintenance

Cultivation

Grow in a moist but well-drained, neutral to acid soil in full sun or partial shade. Choose a sheltered site where the tree will not be damaged by wind or frost.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Well-drained, Moist but well-drained

Soil pH

Acid, Neutral

Light

Partial Shade, Full Sun

Aspect

North, East, West

Exposure

Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 9, Zone 8, Zone 7, Zone 6

Defra's Risk register #1

Plant name

Acer palmatum 'Ornatum' (Japanese maple 'Ornatum')

Common pest name

Apple root knot nematode

Scientific pest name

Meloidogyne mali

Type

Nematode

Current status in UK

Unknown

Likelihood to spread to UK (1 is very low - 5 is very high)

3

Impact (1 is very low - 5 is very high)

4

General biosecurity comments

UK (along with certain other European countries) received potentially infested trees in 1992; but these were destroyed at the end of the trial period and targeted surveillance has failed to find any trace of the nematode. Main impacts are on elm; apple and mulberry and industry should source such material carefully.

Defra's Risk register #2

Plant name

Acer palmatum 'Ornatum' (Japanese maple 'Ornatum')

Common pest name

Alfalfa dwarf; Anaheim disease; California vine disease; Dwarf disease of alfalfa; Dwarf disease of lucerne; Leaf scald of oleander; Leaf scald of plum; Leaf scorch; Phony disease of peach; Pierce's disease of grapevine; Variegated chlorosis of citrus

Scientific pest name

Xylella fastidiosa subsp. multiplex

Type

Bacterium

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

3

Impact (1 is very low - 5 is very high)

4

General biosecurity comments

A bacterial disease with a wide host range detected in Corsica. Although EU regulated; there remains some concern about the risk of introduction. This subspecies is known to be able to thrive in cooler climates. Should an outbreak occur; there would be a need for eradication action which would result in environmental and social impacts.

Defra's Risk register #3

Plant name

Acer palmatum 'Ornatum' (Japanese maple 'Ornatum')

Common pest name

Japanese long scale; Japanese maple scale; Long scale; Japanese; Pear white scale

Scientific pest name

Lopholeucaspis japonica

Type

Insect

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

2

Impact (1 is very low - 5 is very high)

4

General biosecurity comments

Regulated only on Citrus at present; regulation on other hosts needs to be considered. Only likely to be a pest under glass in UK.

About this section

Our plants are under greater threat than ever before. There is increasing movement of plants and other material traded from an increasing variety of sources. This increases the chances of exotic pests arriving with imported goods and travellers, as well as by natural means. Shoot is working with Defra to help members to do their part in preventing the introduction and spread of invasive risks.

Traveling or importing plants? Please read "Don't risk it" advice here

Suspected outbreak? Click here for contact details to report to the relevant authority.

Date updated: 7^th March 2019 For more information visit: https://planthealthportal.defra.gov.uk/