SR-11-D (14)
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Santa Monica, Cal1fornia, August 27, 1981
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TO:
Mayor and C1ty Council
II-D
FROM:
City Staff
SEP 8
198J
SUBJECT: Tree Ma1ntenance and Operatlon
Introduction
Th1S report reVlews the eX1sting street tree malntenance and planting program,
and recommends changes 1n the tree code 1ncluding a revised llst of preferred
street trees for Counell approval.
Backoround
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At the October 29, 1980 Counc1l meeting, ln response to concern about the
planting of Ficus trees. the staff was requested to prepare a report on all
tree maintenance operatlons and to recommend changes in the tree code.
A. Tree Maintenance Functions (current operatlons)
City crews now maintain 26,400 trees on parkways, in parks, and on other
Clty propertles. The Park Div1slon of the Recreatlon and Parks Department
performs the following tree maintenance functlons: triMmlng, plantlng and
replantlng, waterlng of new trees, pest control on a limited as-needed bas1s,
tree well clean-up, removal of fallen and broken branches on a routlne and
emergency call-out basis, re-staking and tying, slgn clearance, removal of
dead trees, code enforcement with regard to illegal plantlngs, and ivy removal.
The tree trimming functlon was transferred to the Park Divislon in August of 1978.
Since that time, a tree trlmming schedule has been developed based on the pr1nclple
of tr1mmlng entlre blocks of trees rather than 1ndividual trees at random. The
schedule gives h1ghest prlority for those trees in greatest need of trlmming Clty
w1de to those of lesser need. Primary cons1derations in develop1ng the schedule are:
degree of hazard to the publlC, potentlal llabillty to the City, potential damage to
the tree, appearance, and nU1sance factor. The goal, wlth no increase 1n staff, 1S
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to trlm the entire city on the average of every four years. Some trees requlre
trlmming more often, l.e. coral trees on San Vicente and Olympic, and Phoenlx
Palms. Others require less, i.e. Magnollas, Llquldambars. Contractual assistance
has been requested and approved for certain tree trimmlng functlons. The second
year of a three year program to slick Phoen1x Palms is complete. Further
contract work w111 be necessary to bring the four year cycle to a reasonable starting
point. Productivity of City crews has been improved by the purchase of new
equipment, by increasing f1e1d supervision, and by the technique of tr1mmlng ent1re
blocks at one tlme.
Park crews have planted 1,535 new trees 1n the past four years and replaced 1,005
trees. There 1S no charge for tree plantlng in res1dentia1 areas except where
bui1ding permlts are requlred. In such cases, the charge is $75 per tree. ThlS
charge also app11es to tree planting ln commerclal areas. There is no charge for
tree replacement. Park crews water new trees for the first 4-6 months, dependlng
upon the season. 7,000 trees were watered last year. Because of the lncrease in
tree watering, contractual assistance 1S belng requested in 1981-1982 so the City
employees can be returned to Park work.
Santa Monica is fortunate to have a very low rate of pest-related problems. Presently,
trees are treated for pests on an as-needed indivldua1 basls. We do not treat whole
streets unless all trees on the street requlre it. The work is done elther by the
Clty'S 11censed pest control applicators or by licensed pest control contractors.
Wlth the exception of recent problems wlth fungus in Phoenix Palms, only 50 other
trees were treated in the last year.
Under present policy, only dead trees or trees that present imminent hazard are
removed. Pictures are taken of the proposed removal and approved by the Dlrector
of Recreation and Parks and the General Services D1rector prior to removal.
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There is an increasing lncldence of ivy planted in parkways groWlng on street trees.
Clty crews have removed it as time permlts, but the problem is beyond our capabillty
at this point. In the past, there was some attempt to charge citizens for the
removal. Apparently this policy was altered due to collection difficulty and citizen
protest. Presently, the property owner is asked to keep the ivy out of the tree once
it has been removed. In the building plan review process, ivy is no longer allowed
to be planted in the parkway.
B. Tree Code - History
The tree program was incorporated in the Santa Monlca municlpal code ln 1953 and
provides for the establishment of tree districts, a list of approved trees. spacing,
wldth of parkways for planting, and outlines tree planting policy. as well as
regulatlons regarding protection of trees, intentlonal damage. attachments to trees.
and pruning or removal of hazardous trees.
Trees ln existence at the time of this enactment could be designated by the Park
Supenntendent as "offlcial" if they met the following criteria:
1) Not diseased or vulnerable to disease.
2) Root system adequate for support.
3) Root system not extremely damaglng to sidewalk and curb.
4) 50% of the street frontage was planted wlth one species.
Because of the impracticality of removlng old established trees, many areas have
trees planted closer together and in parkway strips narrower than recommended.
Examples are the Plne trees north of Montana planted on 25 foot centers rather than
40-60 foot centers, and the Ficus on 21st Street which were planted In parkways less
than four feet wide.
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c. Selectlon Criteria
Using a subjective approach in selecting favorite trees for Street planting 1S
usually unsatisfactory, Several factors must be considered: the visual effect
desired, the functional purpose the tree is to serve, overhead Wlres, and the
cultural characteristics of the tr~e itself. In our mlld cllmate, the effect of
shade trees on temperatures is not as important as lt 1S In cllmates with greater
temperature extremes, and the use of evergreen and diciduous trees becomes less
a factor to be considered.
In Santa Monica, the parkway width and/or the wldth of the sidewalk and setback has
been the chlef determinate In tree se1ection. The second most important factor has
been the ocean breeze and the effect of salt air. Trees that would normally grow
lnland are adversly affected by salt a1r and suffer burn or die back. The type of
tree growlng on the street or ln the area 1S also consldered as an indlcatlon of
the type of tree that will do well. The lack of temperature extremes limits
the varieties that do well In this climate. Some of the larger broadleafed trees
requ1re hotter weather to flourlsh or surVlve. 5011 composition is also a determinate
ln the selection of tree variety. Hard pact soil effects root dlrection and depth
just as loosly packed so11 allows roots to seek greater depth.
Presently, trees are selected by the Park Superlntendent consistent with the
requirements set forth ln section 7603. This system is satisfactory with two
except1ons. F1rst. the tree list in 7602 needs to be modified. Actual field
experience shows some trees listed to be Inapproprlate in Santa Monlca, and some
trees need to be added. Secondly, there is an increasing frequency of tree planting
1n commerclal areas where tree wells are cut in the concrete. Under the present
listlng, tree selection would be too 11miting for aesthetic conslderatlons. Staff
is proposing changes In the tree list to address these problems. (See attached list).
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Those in the preferred catagory will be planted 1n new plantings, wh1le those 1n the
least preferred catagory would be planted only as replacement 1n an already establlshed
planting where the eX1sting trees are doing well. Otherw1se, a different tree wl1l
be designated. Characterlstics of the preferred trees should eliminate most problems
associated with existing plantings, such as raised sidewalks, fru1t dropping, and sap
deposits.
Relief from all problems created by establlshed trees would requlre maJor removals.
Prun1ng, both branch and root, will temporarily correct or slow down a problem, but
as long as the tree continues to grow, the root structure will cont1nue to grow as
well.
The scope of the problem can be seen w1th reference to the 3400 F1CUS trees already
planted in the City. To fully elim1nate th(~ problem of sidewalk and curb damage
would require wholesale re~oval and replace~ent with more suitable varleties at
a cost of $275.00 per tree.
D. Sidewalk Repairs
Presently, the repair of sidewalks is conducted within the General Services Department.
They use several measures to minimize the damage done to the sldewalks by tree roots.
The first is the use of a root trimming machine (acquired in 1979), WhlCh trims the
roots adjacent to the parkway side of the Sldewalk. The success of thlS orocess 1n
reduc1ng sidewalk damage has not yet been determined, since 1t usually takes several
Years for root growth to cause damage after a sidewalk has been reconstructed or
repaired. The root trimming process also has several 11m1tatlons. The root cutter
cannot be used where sprinkler 11nes exist. It1s use may be 11mlted to a depth of no
more than 8 1nches in order to prevent damage to the trees and to maintaln the
stabllity of the root system. There is some questlon whether thlS 1S enough depth
to slgnlficantly retard damaglng root growth.
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A measure WhlCh will be implemented immediately to ~ltigate sidewalk damage lS to
use more closely spaced JOlnts in sidewalk constructlon and replace~ent. ThlS wlll
not eliminate sldewalk daQage, but will reduce the number of square feet that wlll
need repalr In the future. Damaged concrete sldewalk could be replaced with a more
flexlble asphalt materlal. This would reduce future repalr costs because the
asphalt 1S more flexible to expanding roots and because asphalt repairs are 1/3 the
cost of concrete repalrs. The disadvantage of using asphalt materials is that
asphalt has a less attractive appearance, especially when placed next to existing
concrete, and asphalt is less durable to weather and will require some maintenance
unrelated to root damage. General SerVlces recommends that the following course
be followed concerning their roll ln the tree program:
1) Continue the root tree trimming program until effectiveness can be determined.
2) Use the closer sidewalk JOlnts immedlately.
3) Do not use asphalt materials as sldewalk repairs unless cost considerations
outwelgh all other considerations.
E. Prevention of Sldewalk Dam~~
Park Divislon 1S 1n the process of inst1tutlng new planting and ma1ntenance techn1ques
aimed at preventing sidewalk damage. An auger wll1 be used to loosen 5011 as deeply
as posslble below the plant to allow roots and moslture to penetrate downward
rather than hor1zontally. A water jet lmolement ;s belng requested ;n 1981-1982
that will increase deep water penetratlon when new trees are planted. Either
contract or Clty crews wlll use a deep watering devlce durlng the maintenance
perloct. In conJunctlon with Street Divislon's root pruning program a plastlc
barrier will be lnserted along sidewalk edges and on curbllnes.
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F. Future Cons1derations
Desp1te maJor planting efforts by the City over the past several years, these
are still areas of Santa Monica that would benefit from addit10nal trees.
In most cases, the C1ty planting efforts have been restricted by lack of
parkway space. One way to increase the number of trees while moderatlna the
d1rect cost to the C1ty 1S to encourage the planting of trees on pr1vate
property. Such a program may be in the form of a public relat10ns campaign,
Arbor Day observance , or the actual supplying of trees to homeowners at
low or no cost.
Occaslona11y, property owners will choose to have the street tree (s) in front
of the1r home trimmed at the1r own expense by pr1vate contractor. Consldering
the cost of trimm1ng an indivldual tree is usually 1n the hundreds of dollars,
there is significant benef1t to the City 1n encouraging th1S practice. The
existing code section 7610 should be modif1ed to expedite the process. It 1S
recommended the fee requ1red by the code be deleted 1n llght of the value
rece1ved by the City.
The Nat10nal Arbor Day Foundation and U.S. Forest Service sponsor the TREE
CITY USA program to recognize those communities that are effectively managing
thelr tree resources. It appears the Clty of Santa Mon1ca would Qualify
under the four gU1del1nes and have a legally constituted tree body, 1.e.
Recreat10n & Park Depart~ent; have a tree ord1nance; a maintenance program
and budget, and an Arbor Day observance. The benef1ts include public relatIons
for the tree program and technlcal assistance from the forestry service.
Recommendations
1. Direct the Clty Attorney to amend the Tree Code for language and the
following substantive changes:
a. 1ncorporate the updated tree llst 1n Section 7602
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LIST OF APPROVED TREES
(Section 7602)
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The following trees are recommended for plantlng in parkways along streets within the
City. The llst designates "preferred" and "least 'referred" trees based on the growth
charactenstics of existing street trees in Santa Monlca. The 1I1east preferred II trees
would be replaced in existing plantings but would not be used in new plantlngs.
Preferred Trees
Least Preferred Trees
2 ft. parkway or greater
Trachycarpus fJrtunei
nvindmill ~alm)
Callistemon citrinus
(Lemon bottle brush)
Myoporum laetum
(Myoporum)
Nen urn oleander
(Oleander)
Podocarpus macrophyllus
(YelfJ P 1 ne)
4 ft. parkway or greater
Cupanlopsis anacardioides
(Carrotwood)
Erlobotrya deblexa
(Bronze loquat)
Eucalyptus sideroxylon Irosea'
(Red lronbark)
Jacaranda mlmosifolla
Ficus microcarpa (nitida)
(Indi an laurel)
F1CUS retusa
(Laurel Fig)
Prunus carolinlana
(Carolina Cherry)
PnoenlX canarlenSlS
(Canary Island Date Palm)
Melalenca quinquenervia
(cajeput tree)
Pittosporum undulatum
(Victorian box)
Podocarpus gracl1ior
(Fern plne)
Metroslderos excelsus
(New Zealand chrlstmas tree)
Arecastrum roman zoffianum
(Cocos palm)
Butl a capitata
(Pindo palm)
6 ft. parkway or greater
Cinnamomum camphora
(Camphor tree)
Glnkgo blloba
(Maidenhair tree)
Liquldambar tyraciflua 'Palo Alton
(Sweet gum)
Magnolla grandiflora
(Southern magnolla)
CeratQnia siliqua
(Carob tree)
Eucalyptus ficifolia
(Red flowering gum)
Brachychiton diversifolius
(Bottl e tree)
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Preferred Trees
6 ft. parkway or greater
(cont)
Pinus canariensis
(Canary Island Pine)
Pyrus kawakaml
(Evergreen pear)
Tristania conferta
(Brisbane box)
Schinus terebinthifollUS
(Brazllian pepper)
Washingtonla fllifera
(Callfornia Fan Palm)
Washlngtonla robusta
(Mexican fan palm)
8 ft. parkway or greater
Alnus rhomblfolla
(White alder)
liriodendron tullplfera
(Tulip tree)
Plnus Pinea
(Italian Stone Pine)
F1CUS rubiginosa
(Rusty leaf fig)
Ulmus parvlfolla
(Evergreen elm)
10 ft. parkway or greater
Cedrus atlantlca
(Atlas cedar)
F1CUS macrophylla
(Moreton bay flg)
Plnnus pinea
(Itallan Stone Pine)
,
Least Prefe~red Trees
Platanus acerifolia
(London plane)
Pinnus halepensis
(Aleppo pine)
Cedrus deodara
(Deodar cedar)
Existing trees not recommended for planting or replacement:
Dodonaea Vlscosa - Hopseed Bush
Acacia melanoxylon - Blackwood Acacla
Casuarlna cunninghamiana - Horsetall Tree
Grevlllea robusta - Silk Oak
Ilex altaclarensis "Wilson;;" - Wilson Holly
Pinus radlata - Monterey Plne
Cryptomeria Japonica - Japanexe Cedar
Quercus llex - Holly Oak
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b. modify Sectlon 7606 with regard to approval of tree removals by
the Dlrector of Recreatlon and Parks and the General Services Director.
c. in Section 7610, delete reference to $5.00 fee for permits.
2. Staff be dlrected to apply for Tree Clty USA Status.
Prepared by: Donald T. Arnett, Dlrector
Recreatlon and Parks
Stanley Scholl, Director
General Servlces
Doug Stafford
Park Superlntendent
James Lunsford, Director
Planning
Neil Miller
Maintenance Manager