Platanus racemosa (California sycamore)

Botanical name

Platanus racemosa

Other names

California sycamore, Aliso

Genus

Platanus Platanus

Species

P. racemosa - P. racemosa is a vigorous, broadly columnar, deciduous tree with flaking, grey bark and variably-lobed, dark green leaves, velvety when young. Inconspicuous flowers in spring are followed by clusters of green fruit ripening brown.

Native to

California

Foliage

Deciduous

Habit

Broadly columnar

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Colour

Flower

Insignificant or absent in Spring

Foliage

Dark-green in Spring; Dark-green in Summer; Dark-green in Autumn

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How to care

Watch out for

Pests

Generally pest-free

Diseases

This cultivar demonstrates good resistance to anthracnose.

General care

Pruning

Pruning group 1

Propagation methods

Hardwood cuttings, Suckers

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Monthly care advice

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Where to grow

Platanus racemosa (California sycamore) will reach a height of 25m and a spread of 20m after 20-50 years.

Suggested uses

Coastal, Low Maintenance, City, Wildlife

Cultivation

Grow in fertile, humus-rich, well-drained or moist but well-drained soil in full sun. Tolerates drought once established if only planted along the coast or in areas with high water tables. Do not plant close to buildings as its extensive root system will cause structural damage.

Soil type

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

Soil drainage

Well-drained

Soil pH

Acid, Alkaline, Neutral

Light

Full Sun

Aspect

North, South, East, West

Exposure

Exposed, Sheltered

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

Hardy (H4)

USDA zones

Zone 10, Zone 9, Zone 8, Zone 7, Zone 6

Defra's Risk register #1

Plant name

Platanus racemosa (California sycamore)

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 #2

Plant name

Platanus racemosa (California sycamore)

Common pest name

Namangan longhorn beetle

Scientific pest name

Xylotrechus namanganensis

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

Polyphagous pest originating in Asia; some uncertainty regarding risk to UK; further work needed to assess climatic suitability.

Defra's Risk register #3

Plant name

Platanus racemosa (California sycamore)

Common pest name

Scientific pest name

Hylesia nigricans

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

South American moth which could be damaging to broadleaf species if introduced to the UK; as well as having human health impacts. The main pathway is likely to be goods (including non-plant material) imported from South America and awareness raising with the main industry sectors is recommended.

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/