AND MANAGEMENT PLAN brian g. crane · • In 1660, John Berkeley, 1st Baron Berkeley of Stratton (1602-1678), a distinguished Royalist, Cavalier officer and loyal follower of Charles

brian g. crane & associates

MIC For, MI Hort.

BERKELEY

SQUARE

GARDENS

ARBORICULTURAL

ASSESSMENT

AND

MANAGEMENT

PLAN

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Berkeley Square Gardens

OBJECTIVES To consider the history and

current status of the Square

To assess the individual condition of trees present

To determine the environmental status of the Square, insofar as it relates to arboricultural matters.

To determine future management needs – following consultation with owners and managers.

To prepare a phased, time-specific management plan

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• Berkeley Square is one of the best-known locations in the world. In addition to its use by Londoners, it attracts large numbers of international tourists

• The Square is an historic location with a strong place in the story of London.

• The Square supports a population of London planes (Platanus x acerifolia). The trees are highly prized due to their sizes and ages, being possibly some of the largest examples in the world.

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HISTORY

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• In 1660, John Berkeley, 1st Baron Berkeley of Stratton (1602-1678), a distinguished Royalist, Cavalier officer and loyal follower of Charles I was gifted an extensive parcel of land known as Hay Hill Farm to the north of Piccadilly.

• He built Berkeley House on the site.

• The house was demolished in 1733 and Devonshire House a Palladian mansion was built on the land for William Cavendish, 3rd Duke of Devonshire to designs by William Kent It was completed in about 1740 and demolished in 1924.

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WILLIAM KENT (1698 – 1748)

• Architect, landscape designer, funiture maker.

• His tastes were formed during a series of Grand Tours which were financed by a number of rich patrons.

• He was greatly influenced by the Palladian style of architecture.

• Garden design style was influenced by the ‘picturesque’.

• One of his principal pupils was Lancelot ‘Capability’ Brown an exponent of the ‘English Landscape School of design.

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Stowe House

Alexander Pope's Villa

Shotover House

Holkham Hall

Devonshire House

Claremont Garden

Rousham House

Badminton House

44 Berkeley Square, London, (1742-4)

16 St. James Place, London

Oatlands Palace

Euston Hall, Suffolk

Wakefield Lodge, Northamptonshire


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Berkeley Square in 1830. Map published

by Greenwood


PROTECTION AND MANAGEMENT

Since 1975, The Gardens have been managed by Westminster City Council on a 99 year lease management agreement from the owners

They are subject to the London Squares Preservation Act of 1931 and are a Grade II Registered Park and Garden

The Statutory Consultee associated with the Gardens’ Listing is the Garden History Society

Stands in a Conservation Area designated under the Town and Country Planning Act 1990 (as amended)

Trees are subject to a Tree Preservation Order


Berkeley Square Gardens USE OF THE GARDENS

• Social and corporate functions

throughout the year – Erection of marquees and similar,

temporary structures – Vehicle passage through the Gardens,

frequently over the lawned areas. – Physical damage to plants – Soil compaction

• Intensively used for passive

recreation – Particularly during the lunch-time

period - grassed areas and benches are crowded with workers from nearby offices.

– Square is a significant tourist attraction - one of the most well-known (and unlikely) birds in popular cultural history is the nightingale that ‘sang in Berkeley Square’.

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Statues and artworks


Vigorous hybrid between Platanus occidentalis and P. orientalis (the eastern and western planes)

Planted initially in London during the 1700s

Many very large examples of the Georgian and Victorian plantings may still be seen, principally in the larger London Squares and lining the more established roads of the Capital

Probably first arose the in Mediterranean area (although one school of thought maintains that the tree first arose at the Botanic Gardens at Oxford).

The first specimens were probably planted in England in the middle of the 18th Century, although it is contended that the famous London plane in the gardens of the Bishop’s Palace in Ely was planted during the tenure of Bishop Gunning, who held the See from 1674/5 until his death in 1684.

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THE LONDON PLANE

Platanus x acerifolia (Ait.) Willd.


ASSESSMENT

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CONDUCT OF INVESTIGATION

Detailed GPS Tree Survey – using

WCC reference numbers

Soil analysis

Leaf analysis Nitrogen

Chlorophyll fluorescence

Soil Bulk Density

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Tree No Species Height dbh CBP Crown

radius N

Crown

radius NE

Crown

radius E

Crown

radius SE

Crown

radius S

Crown

radius SW

Crown

radius W

Crown

radius NW

Remarks Work required Tree work

priority

Anthracnos

e present

Massaria

present

Swollen basal

formation

1 Platanus x

acerifolia

25 151 6 0.5 0.5 10.5 9.5 11 9.5 11 12.5 Mammal burrowing to south. Trunk

burring. Old pruning wounds on trunk and

crown. 2 x fungal fruiting bodies of

Inonotus hispidus at 14 metres in crown.

Large cavity close to point of crown

formation on north side. Long limb to

north. Scatter of light dead wood

throughout crown

Climbing inspection with

IMLResistograph

1 year No No Yes

2 Platanus x

acerifolia

29 166 0.5 12 15.5 17 16 17.5 0.5 9.5 13 Pronounced root flare. Possible burrowing

to southeast. Cavity to 200 millimetres

depth at 0.75 metres on southwest.

Further shallow cavity with dry decay at 0.5

metres on west. Heavy branch at open fork

to northwest

Insert cable bracing

system to support branch

to northwest

1 year No No Yes

3 Platanus x

acerifolia

18 44 5 6 8.5 8.5 6.5 8.5 5.5 6.5 7 Recent planting. Slight trunk lean. Close

to street light

Clear crown away from

street light

Routine

maintenance

No No No

4 Platanus x

acerifolia

33 205 3 15 14 19 13.5 12 10.5 13 14 Buttress rooting. Inter-buttress hollow to

north at ground level. Root girdling on east

side. Large branch lost from south at 1.8

metres. Heavy limbs to northeast and

northwest. Old pruning wounds throughout

crown. Open crown. Water shoots

forming on large limbs. Hanging branch in

crown. Scatter of light dead wood

throughout crown. Lighting installation

close to base

(1) Remove hanging branch.

(2) Clean crown.

(3) Insert cable bracing system

to support limbs to

northeast and

northwest.

(1) Urgent (2 )

and (3) within 1

year.

No No No

5 Platanus x

acerifolia

28 163 8 10.5 8 7 7 12.5 11.5 13 15 Buttress rooting. Fungal fruiting bodies of

Rigidiporus ulmarius between buttresses on

northeast side. Possible wind stress -

deformation with burring at 2.5 metres. Old

pruning wounds throughout crown. Heavy

branch with small bark wound to northwest.

Trunk fork or division at 15 metres. Sample

and photograph taken

(1) Examination using Picus

ultrasound, IML

Resistograph check

and air spade exposure

of structural roots

SEE APPENDIX D

No No Yes


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Tree 5 Rigidiporus ulmarius

Tree 30 Rigidiporus ulmarius

Tree 6 Perenniporia fraxinea

Tree 1 Inonotus hispidus


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pH H2O Total N Total C C:N K K DEFRA Index Mg Mg DEFRA Index Ca Na Mn S Cu Zn B P(PO4) P(PO4) Index

Lims ID No Details Type Date - % % ratio mg/kg mg/L K mg/kg mg/L Mg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/l P

1110600680

1 5 m east of Tree 4

Soil 15/06/2011

7.43 0.446 6.252 14 322 418 4 194 252 5 5495 33.2 0.47 7.86 0.21 0.10 0.26 71 92 5

1110600681

2 Between Trees

5&7 opp. 'Benares'

Soil 15/06/2011

7.58 0.343 6.565 19 198 257 3 106 138 3 3346 17.4 0.36 6.69 0.46 0.56 0.15 79 103 6

1110600682

3 7 m north of Tree 12

Soil 15/06/2011

7.32 0.364 6.639 18 135 176 2- 120 157 3 3399 24.3 0.77 10.59 0.36 1.23 0.21 66 85 5

1110600683

4 2 m north of Tree 32

Soil 15/06/2011

6.86 0.382 5.376 14 122 159 2- 137 179 4 3829 22.8 0.92 4.98 0.10 0.46 0.21 88 114 6

K Ca Mg Na Al Fe Mn P S B Ba Cd Co Cr Cu Ni Pb Sr Zn As Hg Zr Mo Sb Se Sn

Lims ID No Details Type Date mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg m

g/k

g

mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg

111060068

0

1 5 m east of

Tree 4

Soil 15/06/2

011

6751 9519 4985 346 42909 37243 280 1104 738 27.3 197 0.91 11.16 55.0 89.4 38

.9

283 53 196 17.9 1.47 12.13 1.31 5.79 2.30 19.5

111060068

1

2 Between Trees

5&7 opp.

'Benares'

Soil 15/06/2

011

3694 15083 3357 433 22444 29439 321 1431 844 16.3 222 1.75 10.17 43.7 104.9 30

.8

637 58 355 16.2 1.98 5.71 1.74 7.29 1.45 20.7

111060068

2

3 7 m north of

Tree 12

Soil 15/06/2

011

3629 8662 3149 281 23468 36466 322 1316 815 17.0 238 2.03 10.25 55.3 93.6 35

.6

620 44 398 24.9 1.26 2.54 2.04 10.20 1.90 15.0

111060068

3

4 2 m north of

Tree 32

Soil 15/06/2

011

4559 6354 3499 245 29409 33069 252 1010 696 21.2 140 0.67 9.14 44.0 60.5 28

.6

217 45 141 20.4 0.79 8.34 1.29 4.94 2.19 9.7

Cd Cr Ni Pb As Hg Sn

mg/kg mg/kg mg/kg mg/kg mg/kg mg/k

g

mg/kg

Residential 10.0 200 130 450* 32.0 11 350

Allotment 1.8 230 43.0 8 120

Commercial 230.0 1800 640.0 410 13000


Chlorophyll fluorescence readings

• 7 Trees randomly selected

• 30 samples (leaves taken from each tree – captured using ‘throw-bag’

• Analysed using ‘Pocket Pea’ equipment

• No real cause for concern revealed.

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Relationship Between Soil Bulk Density and

Planting Success or Failure

Bulk Density Planting Success

1.25 – 1.34 Successful: 100%

1.34 – 1.44 Mostly successful: 60%

1.45 – 1.54 Partial failure: 33%

1.55 – 1.64 Predominantly failure: 10%

>1.65 Total failure: 0%

Table 4 Soil Bulk Density Readings

Sample (close to

Tree No)

Soil bulk density reading

Tree 4 1.33 Successful: 100%

Tree 7 1.34 Successful: 100%

Tree 20 1.42 Mostly successful: 60%

Tree 32 1.50 Partial failure: 33%

SOIL BULK DENSITY READINGS


NITROGEN (SPAD) READINGS

The majority of the Nitrogen within a leaf is concentrated in the chlorophyll molecules. Chemical reactions taking place within this molecule produce the carbohydrates necessary to ‘fuel’ plant processes. Nitrogen is also important in the synthesis of proteins. The presence of Nitrogen within a leaf is therefore an indication of the amount of chlorophyll present and thus the leaf’s ability to synthesise carbohydrates. The amount of Nitrogen present in a leaf may be measured using a SPAD meter. 28 Leaf samples were taken from each of 7 randomly selected trees (22.5% of the total population of the Gardens). The average leaf readings, taken with a SPAD meter under laboratory conditions, were then calculated for each tree.

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0

5

10

15

20

25

30

35

40

4 6 7 16 20 21 24

36.6133.12 32.6 33.58

35.65 34.18 33.6 34.837.3

39.8

Legend

Figures on bottom axis indicate tree reference numbers. Green

indicates SPAD reading. Red is lower end of acceptable value

scale, blue shows mean acceptable value and orange upper end of

acceptable value scale


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Tree 6

2011 Picus

tomogram

reading taken at

600 millimetres

from ground

level.

North is

indicated by

sampling point

1.

Tree 6

2007 Picus

tomogram

reading taken at

500 millimetres

from ground

level.

North is

indicated by the

arrow adjacent

to sampling

point 1.


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Tree No 6 – felled January 2012


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Tree 30

2011 Picus tomogram reading taken at just above

root flaring..

North is indicated by the red arrow adjacent to

sampling point 1.

Tree 30

After felling January 2012


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Berkeley Square

Massaria disease

(Splanchnonema

platani)

After felling January

2012

Berkeley Square Gardens The Trees

31 London planes, 29 mature, 2 in early maturity

Apparently 2 main planting periods: The oldest trees were planted by Edward

Bouverie, son of the 1st Viscount Folkestone in 1759 – not as reported in some papers during the Victorian period - these are probably Trees 1, 2, 4, 5, 6, 7, 8, 10, 16, 21, 22, 23, 24, 25, 26, 27, 29, 31 and 32 – dbhs around 2 metres.

There seem to be a number of trees dating from the Victorian period probably Trees 11, 12, 13, 14, 17, 18, 19, 20, 28, 29 and 30 – these are characterised by swollen trunk bases and dbhs around 1 metre.

Trees 3 and 27 have been planted since Westminster took on management of the Square Gardens in 1975.

There is evidence of poor clonal stock – many tree have formed crotches with co-dominant stems

Crowns are open and ‘lion-tailed’

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FUTURE MANAGEMENT

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IDENTIFIED ISSUES:

Ageing population Pathogen colonisation

Replanting

Species selection

People pressure Events

Soil compaction

Physical damage

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Objective Achieve by Implementation Timing Additional

management

considerations and

notes

Implementation by

Allow continued public

access to Berkeley

Square Gardens

Westminster C C and

owners

Ensure safety of public

using the Gardens and

other persons who may

be affected by such use

Maintain trees in safe

condition

Detailed inspection of

trees identified with butt

decaying fungi (Trees 5,

6, 30 and possibly 24)

Urgent

Inspections have

been carried out

(see Appendix D)

Westminster C C

Remove identified

dangerous trees (Trees 6

and 30)

Urgent

Westminster C C

Appropriate tree surgery,

including installation (and

inspection) of cable

bracing systems.

Within time periods

specified at

Appendix E

Westminster C C

Monitoring of tree health.

Ongoing

Westminster C C

Inspection and reporting

Remedial safety pruning

Particular attention to

incidences of Inonotus

hispidus and

Splanchnonema platani

(Massaria disease)

At least annual

Westminster C C



Objective Achieve by Implementation Timing Additional management

considerations and

notes

Implementation

by

Ensure continuity of tree

cover and maintenance of

arboricultural elements of

historic landscape

(continued)

Tree protection during

events

Observe Root Protection

Areas (Appendix C,

Drawing BGC3/BSG RPAS

Rev 0)

Protect aerial parts

Prepare outline

specification for tree

protection. To include

measures for ground

protection within Root

Protection Areas from

vehicle damage.

Contractors to present

detailed method

statement for approval by

Westminster CC before

works begin.

By November 2011

Contractor method

statements to be

acceptable to

Westminster and

presented in time to

enable modification,

etc

Westminster CC

Tree protection during

erection of statues,

installation of any

underground facility,

service etc. Note: this

protection should extend to

works carried out outside

the Gardens boundaries.

Observe Root Protection

Areas (Appendix C,

Drawing BGC3/BSG RPAS

Rev 0)

Protect aerial parts

Prepare outline

specification for tree

protection. To include

measures for ground

protection within Root

Protection Areas.

Contractors to present

detailed method

statement, prepared to

British Standard 5837

(2005) ‘Trees in Relation

to Construction’ for

approval by Westminster

CC before works begin.

As required

Contractor method

statements to be

acceptable to

Westminster and

presented in time to

enable modification,

etc

Westminster CC




considerations and

notes

Implementation

by




historic landscape

Management of existing

trees to prolong safe,

useful life expectancies

Inspection and monitoring

of tree health. Particular

attention to incidences of

Inonotus hispidus and

Splanchnonema platani

(Massaria disease)

Appropriate tree surgery,

including installation of

cable bracing systems.

Inspection and reporting

Remedial safety pruning

Soil management—relief of

compaction using hollow-

tining and air-spading when

necessary

Ongoing/annual

Hollow-tining—twice

annually

To be carried out in

accordance with good

turf-culture practice

Westminster

C C

Westminster

C C




considerations and

notes

Implementation by




historic landscape

(continued)

Planting (new planting

and replacement planting)

Select planting sites (se

Appendix C, Drawing

BGC4/BSG PLANTING

Rev 0.)

Summer 2011

BGC Associates (if

instructed) with

Westminster C C

Select and identify

planting stock

Summer/autumn 2011

Consider dangers of

monoculture in light of

increasing disease

threat to London

plane.

BGC Associates (if

instructed) with

Westminster C C

Prepare detailed planting

and aftercare

specification

If semi-mature sizes

selected – supplier to

prepare planting

specification for

approval by

Westminster C C and

Square owners.

Planting specification

to include for formative

pruning by skilled

operatives

BGC Associates (if

instructed) with

Westminster C C

Import stock for growing

on in selected nursery, if

necessary

Winter 2011/12

BGC Associates (if

instructed) with

Westminster C C and

selected nursery

Prepare detailed planting

and aftercare

specification

By November 2011

BGC Associates (if

instructed) with

Westminster C C

Planting

Winter 2011/2012 if

suitable stock available

BGC Associates (if

instructed) with

Westminster C C



PLANTING CONSIDERATIONS

Choice of species

History

Local feeling

Size of planting material

Provenance and quality of planting material

Planting method

Post-planting maintenance


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Masssaria (Splanchnonema platani)

Previously found in Germany and the Low Countries, which has recently appeared in London, affecting both weakened and apparently healthy trees. It appears specific to London plane. The fungus attacks branches, weakening them from the upper side and progressing downwards through the branch, often resulting in branch failure. Because the damage occurs on the upper side, of the branch, it can be difficult to detect. Decay progresses very swiftly, indicating a need for very frequent aerial inspection. Diseased branches are severely weakened, must be considered dangerous and should be removed immediately they are identified

Anthracnose (Apoignomonia veneta)

This fungal disease is common on London planes within the capital. It causes discoloration (with lack of function) of the leaves, with shoot and bud dieback and loss.

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THE LONDON PLANE

THREATS .

Phellinus punctatus

A fungus causing cankers on the bark of

London planes, weakening the branches.

It is common in France and Italy and was

identified in Britain in 2008.

Inonotus hispidus

This fungus has been widely associated

with ash (Fraxinus excelsior) in Britain,

for many years; however, it is becoming

more common on London plane. It

causes a degradation of timber strength,

although this appears more marked with

ash, when the fungus frequently causes

failure. The stem cankers caused by the

fungus may have a significant impact on

the safety of affected branches. A canker

of this species was noted initially on

London plane in Dulwich in 2006.




Canker stain (Ceratocystis fimbriata f. sp. platani)

This fungus is widespread in Europe, particularly in the more southerly regions, where management of London planes by ‘pleaching’ or other intensive methods is common, the fungus being commonly spread on pruning tools.

It causes a severe wilting, due to occlusion of the conducting tissue. The fungus may also spread by root grafting and in soil water.

Probably arrived from the USA during WW II. Its presence in the UK has not yet been confirmed, but it is considered a severe threat by the Forestry Commission and wood products derived from London plane (including plants) are subject to The Plant Health (Forestry) Order 2005. Recently, colonisation by this fungus necessitated the felling of some 2,500 London planes along the Canal du Midi in France.

One French nursery has a patent on a cultivar P. a. ‘Platanor’, which shows some resistance to C. fimbriata, however, the clone is of poor form and has not performed well in trials in the UK.

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THE LONDON PLANE

THREATS .

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THE END

Thank you for your attention

Documents

AND MANAGEMENT PLAN brian g. crane · • In 1660, John Berkeley, 1st Baron Berkeley of Stratton (1602-1678), a distinguished Royalist, Cavalier officer and loyal follower of Charles