Watering Street Trees

7/30/2019 Watering Street Trees

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Watering Street Trees in Santa Monica

Watering trees is extremely important to their growth, health and ability to produce the

important environmental benefits that we as a community rely on. However, like anything

else, too much of a good thing can be detrimental. By following some basic guidelines you

can have healthy street trees and conserve water at the same time.

FUNDAMENTALS OF WATERING STREET TREES

The species, age of tree and type of soil have a bearing on how much to water.

o Some types of soil hold water longer than other types.

o Some types of soil dry out quicker than other types.

o Watering young trees is different from watering mature trees.

o Some species do not require as much water as others might regardless of age.

See Attachment 1 for a list of watering needs of individual species.

To find out what species your street tree is contact the Community Forester at

[email protected].

o The seasons and weather conditions influence when to water.

Checking soil moisture content throughout the year will tell when a tree needs

water.

o Surface grade dictates how fast the soil can take the water.

Apply too much at once or too often and you get surface runoff or puddles.

KNOW THE TYPE OF SOIL

It is important that sprinkler systems are properly designed and maintained so they apply

water at a rate low enough to allow all it to infiltrate into the soil without running off or

creating puddles somewhere its not supposed to.
mailto:[email protected]:[email protected]:[email protected]


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The rate at which soil can absorb or take in water is the infiltration rate. The rate at which a

sprinkler system applies water is called the application rate. If the application rate is higher

than the soil's infiltration rate surface runoff is achieved, resulting in water collecting on the

surface and/or flowing away from where it was supposed to go. This wastes water as it

doesnt provide the tree with the water it needs. This condition can be offset by applying

repeating shorter water cycles that gives to sol time to absorb the moisture in between

cycles.

The irrigation system shown in

the photo at left shows a front

yard landscape with a steep

grade down to the sidewalk.The system has been running

long enough to pass the point

of runoff and the water applied

from this point forward is

wasted.

To avoid this problem the system should be set with short cycles and long intervals in

between each cycle. This allows the soil to absorb the water as it is applied.

In order to have an idea of the infiltration rate it helps to know the type of soil. A general

rule to follow when applying irrigation is: sandy soil requires water on a more frequent basis

and clay soils require less water on an infrequent basis.

An easy way to determine the type of soil:

Dig down about four inches and take a sample of moist soil about the size of a

marble.

o If it can be rolled up into a tube thinner than a pencil and hold its shape, then its

clay soil.

o If the soil breaks apart easily and has a consistent, gritty texture, it is sandy soil.


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o If the soil contains a lot of organic matter of varying size and consistency, it is

loam. Loamy soil can also vary from clay loam or sandy loam.

Loamy soil that is easy to break apart into small particles is sandy loam.

Loamy soil that breaks apart into large chunky particles is clay loam.

Soil with the right amount of water should be moist but not saturated. A simple test to

check moisture content is to take a handful of soil and squeeze it tightly then release the

pressure. If the soil retains its shape and is not sticky or oozing water, the moisture content

is favorable.

Another consideration is the seasonal changes in weather. During spring and fall, the days

are shorter and cooler and the soil temperature drops, and trees need less water. As thedays get longer and warmer, trees need more water. As the seasons change, the

frequency of watering needs to be adjusted accordingly. This is usually done by reducing

the number of days between each time you need to water and reducing the amount that is

actually applied to the soil. If no adjustments are made throughout the seasons, over-

watering or under-watering occurs, which in turns leads to poor tree health.


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GUIDELINES FOR WATERING STREET TREES

Check the Community Foresters list of water requirements for street trees to get an

idea of how much water your street tree needs. (Attachment 1)

Key factors to remember when watering street trees:

o Species

There are over 225 different species of trees in Santa Monica and many of them

require different amounts of water at different times of the year. Santa Monicas

forest is primarily made up of trees that flourish in a moderate climate with

naturally dry conditions. Many species found in Santa Monica do not require

regular water and actually thrive when they receive minimal amounts. Other

species require no irrigation during the summer months as it is detrimental to

their health. Mature or established trees usually can get by with infrequent

watering depending on the species of tree.

Most of Santa Monicas street trees require a climate with long, hot summers

and mild winters with a moderate amount of rainfall. They do best in sandy

loam soil but can tolerate other types of soils.

The most important area to water for deciduous trees is within the dripline

(from the trunk to the outer edges of the trees branches). For evergreens, water 3-5 feet beyond the dripline on all sides of the tree.

o Current age and size

Older trees are sensitive to increased amounts of water. Trees that have been

thriving on a certain level of soil moisture and then subjected to increased

amounts can respond in different ways.

Increased shoot growth adds new foliage and weight to the limbs in the

canopy and increases pruning requirements. In order to reduce the potential

for limb failures pruning cycles need to be increased.


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Too much water can also kill roots from lack of oxygen in the soil. Mature

trees that suffer from too much water in the soil will respond with dead tips,

dieback throughout the canopy and excessive leaf drop. In extreme cases,

trees with dead roots can fall over.

The tree in the photo at right is a mature drought tolerant tree that has a

sparse canopy and chlorotic foliage because of regular watering. This isevident by the dieback in the tips of the tree seen in the photo at left.

The photo at right

shows the trunk

base clear of turf.

This helps prevent

damage to the

trunk from water,

lawn mowers or

line trimmers and

maintains a strong

healthy trunk base.


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Water on the trunkcreates conditions fordecay to progresswhen there arewounds at the base ofthe tree.

Water on the trunk can lead to decay

if there are wounds at the base of

the tree. This eventually weakens

the trunk and creates a potential for

total tree failure.


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There are several fungal diseases known to afflict trees that thrive in of

southern Californias climate. The diseases that infect these trees can cause

considerable damage and even the demise of a street tree. These problems

mainly arise due to conditions that are different from their native habitat.

Conditions such as summer watering or excessive watering in the winter

result in fungi, bacteria and viruses in the soil that trees cannot withstand or

compete with. This condition can ultimately lead to the failure of a mature

tree in spite of a healthy appearing canopy.

The photo at right and

below show the fruiting

bodies of two fungi thatare commonly

associated with trees

that have been wounded

and suffer from internal

decay. Improper or

excessive watering at

the base of a tree

creates conditions for

these fungi to grow and accelerate the decay process. When trees display

these fruiting bodies it is an indication of extensive internal decay.

Report a tree with

fruiting bodies of fung

[email protected]
mailto:[email protected]:[email protected]


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When watering trees it helps to understand the following facts about roots.

o A trees root mass is its foundation and provides the structural support it needs to

remain standing upright. Over watering leads to damage to that foundation and

can affect the stability of a street tree.

o Most if not all of a street trees roots are found in the upper 2 feet of soil.

o Most, if not all roots are found where water, nutrients and oxygen are readily

absorbed.

o The distances that roots can spread horizontally, and the spot where most of the

moisture is absorbed, are directly related.

o Trees need oxygen for their roots. Too much water in the soil interferes with the

roots ability to exchange oxygen, leads to root rot and the eventual decline or

failure of a tree.

o The roots of a street tree can extend up to four times the diameter of its canopy

which places much of the root mass in a front yard landscape. Watering a front

yard landscape forces the tree to develop its network of roots under the sidewalk

and in a front yard.

o Deep and/or infrequent watering forces a tree to develop a root system that is far

reaching and/or deep.

o Regular water for a front yard landscape allows street trees to develop a shallow

root system that does not extend any farther than it has to in order to reach a

source of moisture.


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LEVELS OF WATERING

None

o Exactly what is says. Trees that do

not need water will thrive in dry soil

are healthier and have a stronger root

base. The tree in the photo at right

doesnt need watering as it gets all of

its moisture from the adjacent

landscape on the opposite side of the

sidewalk.

Minimalo Water applied by drip either through a

designed drip system or a temporary watering bag in order to establish young

trees.

o The amount of water a tree needs also depends on the season as well:

During the months of April - October:

A short water cycle in the morning once or twice a week is the best.

During the months of November - March:No need for supplemental water during the winter season


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Occasional Flooding

o Trees that need moderate amounts of

moisture but are growing in poor

draining soils perform better when the

soil is flooded periodically, allowing a

long period in between each water

cycle to allow the moisture to drain

through the soil. The tree in the photo

at right requires occasional flooding in

order to maintain moisture in the soil.

However, it would not grow well if its

trunk base was watered every day.

Regular

o Street trees that need regular water

such as the tree in the photo at right,

can thrive on what is usually applied to

the average landscape. This developsshallow roots that have the potential to

disrupt surrounding hardscapes that

are within a trees normal growth zone.

o Regular water can also be applied

through a drip system, or manually.

o To learn best management practices

for landscaping and irrigating

parkways read the Citys Parkway

Policy (Attachment 2).


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Moderate

o Street trees that need a

moderate amount of water

need regular water in larger

quantities. Trees that need

this much moisture are faster

growing or develop large

canopies.

Ampleo Exactly what is says, ample amounts of water. Street trees that need ample

amounts of water will

show signs of stress if

they do not get the water

they need. Trees that

need ample amounts of

water can have largecanopies or come from a

riparian habitat, the

tropics or the northern

part of California.


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Botanical Name Common NameSupplemental

IrrigationRequirements

Summer Irrigationrecommendation

Winter Irrigrecommenda

Acacia baileyana BAILEY ACACIA None Young trees only None

Acacia decurrens GREEN WATTLE None Young trees only None

Acacia melanoxylon BLACK ACACIA None Young trees only None

Acacia spp. ACACIA None Young trees only None

Acer palmatum JAPANESE MAPLE Occasional flooding Moderate None

Acer saccharinum SILVER MAPLE Moderate Minimal Moderate

Agonis flexuosa PEPPERMINT TREE Minimal Minimal Minimal

Albizia distachya PLUME ALBIZIA Minimal - None Minimal None

Albizia julibrissin SILK TREE Moderate Minimal None Minimal

Alnus cordata ITALIAN ALDER Regular Regular Regular

Alnus rhombifolia WHITE ALDER Regular Regular Regular

Araucaria bidwillii BUNYA-BUNYA Regular Regular Regular

Araucaria columnaris STAR PINE Regular Regular Regular

Araucaria heterophylla NORFOLK ISLAND PINE Regular Regular Regular

Arbutus unedo STRAWBERRY TREE Moderate Minimal Moderate Minimal Minimal

Archontophoenix alexandrae ALEXANDRA PALM Moderate Minimal Moderate Minimal Minimal

Archontophoenixcunninghamiana

KING PALM Moderate Minimal Moderate Minimal Minimal

Bauhinia blakeana HONG KONG ORCHID TREE Moderate Minimal Moderate Minimal Minimal

Bauhinia variegata PURPLE ORCHID TREE Moderate Minimal Moderate Minimal Minimal

Betula pendula EUROPEAN WHITE BIRCH Regular Regular Regular

Betula spp. BIRCH Regular Regular Regular

Brachychiton populneus BOTTLE TREE Moderate Minimal Minimal Minimal

Brahea armata MEXICAN BLUE PALM Minimal Minimal Minimal

Brahea edulis GUADALUPE PALM Minimal Minimal Minimal

Broussonetia papyrifera PAPER MULBERRY Moderate Minimal Moderate Minimal None

Butia capitata PINDO PALM Regular Regular Regular

Calliandra tweedii TRINIDAD FLAME BUSH Minimal - None Minimal None

Callistemon citrinus LEMON BOTTLEBRUSH Minimal None None

Callistemon citrinus 'Violaceus' PINK BOTTLEBRUSH Moderate Moderate Moderate

Callistemon viminalis WEEPING BOTTLEBRUSH Moderate Moderate Moderate

Calocedrus decurrens INCENSE CEDAR Minimal - None Minimal None

Calodendrum capense CAPE CHESTNUT Regular Regular Regular

Casimiroa edulis WHITE SAPOTE Regular Regular Regular

Cassia excelsa CROWN OF GOLD TREE Moderate Minimal Moderate Minimal None

Cassia leptophylla GOLD MEDALLION TREE Moderate Minimal Moderate Minimal None

Attachment 1: Water Requirements by Species


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Castanea spp. CHESTNUT Moderate Minimal Moderate Minimal Moderate

Casuarina cunninghamiana RIVER SHE-OAK Minimal Young trees only None

Casuarina stricta DROOPING SHE-OAK Minimal Young trees only None

Cedrus atlantica ATLAS CEDAR Minimal None None

Cedrus atlantica 'Pendula' CEDAR WEEPING Minimal Young trees only None

Cedrus deodara DEODAR CEDAR Minimal Young trees only None

Cedrus spp. CEDAR Minimal Young trees only None

Celtis spp. HACKBERRY Moderate Minimal Moderate Minimal None

Ceratonia siliqua CAROB Minimal None None

Cercis canadensis EASTERN REDBUD Minimal None None

Cercis occidentalis WESTERN REDBUD Minimal None None

Chamaerops humilis MEDITERRANEAN FAN PALM Moderate Moderate None

Chionanthus retusus CHINESE FRINGE TREE Regular Regular Regular

Chorisia speciosa SILK-FLOSS TREE Moderate Minimal Moderate Minimal Minimal

Cinnamomum camphora CAMPHOR TREE Moderate Minimal Young trees only None

Citrus limon LEMON Regular Regular Regular

Citrus sinensis ORANGE Regular Regular Regular

Cordyline australis DRACAENA Regular Regular Regular

Cotoneaster lacteus RED CLUSTERBERRY Moderate Minimal Moderate Minimal Minimal

Cryptomeria japonica JAPANESE CEDAR Regular Regular Regular

Cupaniopsis anacardioides CARROTWOOD Minimal None None

Cupressocyparis leylandii LEYLAND CYPRESS Regular Regular Regular

Cupressus macrocarpa MONTEREY CYPRESS Moderate Minimal None Minimal

Cupressus sempervirens ITALIAN CYPRESS Minimal Minimal Minimal

Cupressus spp. CYPRESS Minimal Minimal Minimal

Diospyros virginiana AMERICAN PERSIMMON Regular Regular Regular

Dodonaea viscosa HOPSEED Moderate Minimal None Minimal

Dracaena draco DRAGON TREE Moderate Moderate Moderate

Duranta repens SKY FLOWER Regular Regular Regular

Eriobotrya deflexa BRONZE LOQUAT Regular Regular Regular

Eriobotrya japonica EDIBLE LOQUAT Regular Regular Regular

Erythrina bidwillii BIDWILLS CORAL TREE Regular Regular Regular

Erythrina caffra KAFFIRBOOM CORAL TREE Regular Regular Regular

Erythrina coralloides NAKED CORAL TREE Regular Regular Regular

Erythrina crista-galli COCKSPUR CORAL TREE Regular Regular Regular

Erythrina spp. CORAL TREE Regular Regular Regular

Eucalyptus camaldulensis RED GUM Minimal None Minimal


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Eucalyptus cinerea ASH GUM Minimal None Minimal

Eucalyptus citriodora LEMON-SCENTED GUM Minimal None Minimal

Eucalyptus cladocalyx SUGAR GUM Minimal None Minimal

Eucalyptus cornuta YATE Minimal None Minimal

Eucalyptus ficifolia RED FLOWERING GUM Minimal None Minimal

Eucalyptus globulus BLUE GUM Minimal None Minimal

Eucalyptus grandis FLOODED GUM Minimal None Minimal

Eucalyptus leucoxylon WHITE IRONBARK Minimal None Minimal

Eucalyptus maculata SPOTTED GUM Minimal None Minimal

Eucalyptus nicholiiNICHOL'S WILLOW LEAFEDPEPPERMINT

Minimal None Minimal

Eucalyptus polyanthemos SILVER DOLLAR GUM Minimal None Minimal

Eucalyptus rudis DESERT GUM Minimal None Minimal

Eucalyptus sideroxylon RED IRONBARK Minimal None Minimal

Eucalyptus spp. EUCALYPTUS Minimal None Minimal

Eucalyptus torquata CORAL GUM Minimal None Minimal

Eucalyptus viminalis MANNA GUM Minimal None Minimal

Euphorbia cotinifolia CARIBBEAN COPPER TREE Minimal None Minimal

Feijoa sellowiana PINEAPPLE GUAVA Regular Regular Regular

Ficus 'Alii' FICUS ALII Regular Regular Regular

Ficus benjamina WEEPING FIG Regular Regular Regular

Ficus carica EDIBLE FIG Regular Regular Regular

Ficus elastica RUBBER TREE Regular Regular Regular

Ficus macrophylla MORETON BAY FIG Regular Regular Regular

Ficus microcarpa WEEPING INDIAN LAUREL FIG Regular Regular Regular

Ficus microcarpa 'Green Gem'GREEN GEM INDIAN LAURELFIG

Regular Regular Regular

Ficus microcarpa 'Nitida' INDIAN LAUREL FIG Regular Regular Regular

Ficus rubiginosa RUSTY LEAF FIG Regular Regular Regular

Ficus spp. FIG Regular Regular Regular

Ficus watkinsiana WATKINS FIG Regular Regular Regular

Fraxinus uhdei SHAMEL ASH Moderate Minimal None Minimal

Fraxinus uhdei 'Tomlinson' TOMLINSON ASH Moderate Minimal None Minimal

Fraxinus velutina ARIZONA ASH Moderate Minimal None Minimal

Fraxinus velutina 'Dr Pironne' ASH ARIZONA Moderate Minimal None Minimal

Fraxinus velutina 'Modesto' MODESTO ASH Moderate Minimal None Minimal

Geijera parviflora AUSTRALIAN WILLOW Moderate Minimal None Minimal

Ginkgo biloba MAIDENHAIR TREE Moderate Minimal Moderate Minimal Moderate

Ginkgo biloba 'Autumn Gold' GINKGO AUTUMN GOLD Moderate Minimal Moderate Minimal Moderate


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Grevillea robusta SILK OAK Minimal None Minimal

Hakea laurina PINCUSHION TREE None None None

Harpephyllum caffrum KAFFIR PLUM Moderate Minimal Moderate Minimal Moderate

Hymenosporum flavum SWEETSHADE Moderate Moderate Moderate

Jacaranda mimosifolia JACARANDA Moderate

Minimal Minimal - None Minimal

Juglans hindsii CALIFORNIA BLACK WALNUT None None None

Juniperus chinensis CHINESE JUNIPER Minimal Minimal None

Juniperus chinensis 'Torulosa' HOLLYWOOD JUNIPER Minimal Minimal None

Juniperus spp. JUNIPER Minimal Minimal None

Koelreuteria bipinnata CHINESE FLAME TREE Moderate Moderate Minimal

Koelreuteria paniculata GOLDENRAIN TREE Moderate Moderate Minimal

Lagerstroemia indica CRAPE MYRTLE Moderate Minimal Young trees only None

Lagerstroemia indica'Muskogee'

CRAPE MYRTLE Moderate Minimal Young trees only None

Lagerstroemia indica'Tuscarora'

CRAPE MYRTLE TUSCARORA Moderate Minimal Young trees only None

Lagunaria patersonii PRIMROSE TREE Moderate Minimal Moderate Minimal None

Laurus nobilis SWEET BAY Moderate Minimal Moderate Minimal None

Leptospermum laevigatum AUSTRALIAN TEA TREE Moderate Minimal Moderate Minimal None

Leptospermum spp. TEA TREE Moderate Minimal Moderate Minimal None

Leucaena glauca WHITE POPINAC Moderate Minimal Moderate Minimal None

Liquidambar orientalis ORIENTAL SWEETGUM Moderate Moderate Moderate

Liquidambar styraciflua AMERICAN SWEETGUM Moderate Moderate Moderate

Liquidambar styraciflua

'Burgundy' BURGUNDY SWEETGUM Moderate Moderate ModerateLiquidambar styraciflua'Rotundiloba'

ROUND-LEAFED SWEETGUM Moderate Moderate Moderate

Liriodendron tulipifera TULIP TREE Regular Regular Regular

Lophostemon confertus BRISBANE BOX Minimal None None

Lyonothamnus floribundusFERN-LEAF CATALINAIRONWOOD

Moderate Minimal Moderate Minimal Minimal

Macadamia tetraphylla ROUGH-SHELL MACADAMIA Regular Regular Regular

Magnolia grandiflora SOUTHERN MAGNOLIA Moderate Moderate Minimal

Magnolia grandiflora 'SamuelSommer'

MAGNOLIA SAMUEL SOMMER Moderate - Regular Moderate -Regular Moderate -Re

Malus sylvestris EDIBLE APPLE Moderate - Regular Moderate -Regular Moderate -Re

Maytenus boaria MAYTEN TREE Moderate - Regular Moderate - Regular Moderate - Re

Melaleuca armillaris DROOPING MELALEUCA Minimal None None

Melaleuca ericifolia HEATH MELALEUCA Minimal None None

Melaleuca nesophila PINK MELALEUCA Minimal None None

Melaleuca quinquenervia CAJEPUT TREE Minimal None None

Metrosideros excelsusNEW ZEALAND CHRISTMASTREE

Minimal Young trees only None

Morus alba WHITE MULBERRY Regular Regular Regular


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Musa spp. BANANA Ample Ample Ample

Myoporum laetum MYOPORUM Minimal - None Minimal - None None

Myrtus communis TRUE MYRTLE Moderate Minimal Moderate Minimal Low

Neodypsis decaryi TRIANGLE PALM Regular Regular Regular

Nerium oleander OLEANDER Minimal None None

Olea europaea OLIVE Minimal None None

Persea americana AVOCADO Regular Regular Regular

Persea borbonia RED BAY Regular Regular Regular

Phoenix canariensis CANARY ISLAND DATE PALM Moderate Minimal None None

Phoenix dactylifera DATE PALM Regular Regular Regular

Phoenix loureri DATE PALM Regular Regular Regular

Phoenix reclinata SENEGAL PALM Regular Regular Regular

Phoenix roebelenii PYGMY DATE PALM Regular Regular Regular

Pinus brutia CALABRIAN PINE Minimal Young trees only None

Pinus canariensis CANARY ISLAND PINE Minimal Young trees only None

Pinus densiflora JAPANESE RED PINE Minimal Young trees only None

Pinus edulis PINON PINE Minimal Young trees only None

Pinus halepensis ALEPPO PINE Minimal Young trees only None

Pinus pinaster CLUSTER PINE Minimal Young trees only None

Pinus pinea ITALIAN STONE PINE Minimal Young trees only None

Pinus radiata MONTEREY PINE Minimal Young trees only None

Pinus thunbergiana JAPANESE BLACK PINE Minimal Young trees only None

Pinus torreyana TORREY PINE Minimal Young trees only None

Pistacia chinensis CHINESE PISTACHE Minimal - None Minimal - None None

Pittosporum crassifolium KARO Moderate Moderate Minimal

Pittosporum phillyreoides WILLOW PITTOSPORUM Moderate Moderate Minimal

Pittosporum rhombifolium QUEENSLAND PITTOSPORUM Moderate Moderate Minimal

Pittosporum spp. PITTOSPORUM Moderate Moderate Minimal

Pittosporum tobira MOCK ORANGE Moderate Moderate Minimal

Pittosporum undulatum VICTORIAN BOX Moderate Moderate Minimal

Pittosporum viridiflorum CAPE PITTOSPORUM Moderate Moderate Minimal

Platanus acerifolia LONDON PLANE Moderate Moderate Moderate

Platanus acerifolia 'Bloodgood' LONDON PLANE BLOODGOOD Moderate Moderate Moderate

Platanus occidentalis AMERICAN SYCAMORE Moderate Moderate Moderate

Platanus racemosa CALIFORNIA SYCAMORE Moderate Moderate Moderate

Platycladus orientalis ORIENTAL ARBORVITAE Moderate Moderate Minimal

Podocarpus gracilior FERN PINE Regular Regular Regular


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Podocarpus henkelii LONG-LEAFED YELLOWWOOD Regular Regular Regular

Podocarpus macrophyllus YEW PINE Minimal Minimal Minimal

Podocarpus nagi PODOCARPUS NAGI Regular Regular Regular

Populus alba WHITE POPLAR Regular Regular Regular

Populus nigra 'Italica' LOMBARDY POPLAR Regular Regular Regular

Prunus amygdalus ALMOND Moderate - Regular Moderate - Regular Moderate - Re

Prunus armeniaca APRICOT Moderate - Regular Moderate - Regular Moderate - Re

Prunus blireiana FLOWERING PLUM Moderate - Regular Moderate - Regular Moderate - Re

Prunus caroliniana CAROLINA LAUREL CHERRY Moderate - Regular Moderate - Regular Moderate - Re

Prunus cerasifera PURPLE-LEAF PLUM Moderate - Regular Moderate - Regular Moderate - Re

Prunus domestica PLUM Moderate - Regular Moderate - Regular Moderate - Re

Prunus lyonii CATALINA CHERRY Moderate - Regular Moderate - Regular Moderate - Re

Prunus 'Mt Fuji' CHERRY MT FUJI Moderate - Regular Moderate - Regular Moderate - Re

Prunus persica PEACH Moderate - Regular Moderate - Regular Moderate - Re

Prunus serrulataJAPANESE FLOWERINGCHERRY

Moderate - Regular Moderate - Regular Moderate - Re

Psidium cattleianum STRAWBERRY GUAVA Regular Regular Regular

Pyrus calleryana ORNAMENTAL PEAR Moderate Moderate Moderate

Pyrus communis FRUITING PEAR Moderate Moderate Moderate

Pyrus kawakamii EVERGREEN PEAR Moderate Moderate Moderate

Quercus agrifolia COAST LIVE OAK Minimal None Minimal - No

Quercus ilex HOLLY OAK Minimal None Minimal - No

Quercus suber CORK OAK Minimal None Minimal - No

Quercus virginiana SOUTHERN LIVE OAK Minimal None Minimal - No

Radermachera sinica CHINA DOLL Regular Regular Regular

Ravenea rivularis MAJESTY PALM Regular Regular Regular

Roystonea oleracea SOUTH AMERICAN ROYAL PALM Regular Regular Regular

Roystonea regia CUBAN ROYAL PALM Regular Regular Regular

Salix matsudana 'Tortuosa' CORKSCREW WILLOW Regular Regular Regular

Schefflera actinophylla QUEENSLAND UMBRELLA TREE Regular Regular Regular

Schinus molle CALIFORNIA PEPPER Minimal Minimal None

Schinus terebinthifolius BRAZILIAN PEPPER Minimal None None

Sequoia sempervirens COAST REDWOOD Ample Ample Ample

Sequoiadendron giganteum GIANT SEQUOIA Ample Ample Ample

Stenocarpus sinuatus FIREWHEEL TREE Moderate Moderate Moderate

Strelitzia nicolai GIANT BIRD OF PARADISE Moderate Moderate Moderate

Syagrus romanzoffianum QUEEN PALM Moderate Moderate Minimal

Syzygium paniculatum BRUSH CHERRY Moderate Moderate Moderate


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Tabebuia chrysotricha GOLDEN TRUMPET TREE Regular Regular Regular

Taxodium mucronatum MONTEZUMA CYPRESS Minimal - None Minimal - None None

Thevetia peruviana YELLOW OLEANDER Minimal None Minimal

Tipuana tipu TIPU Regular Regular Regular

Trachycarpus fortunei WINDMILL PALM Regular Regular Regular

Tristaniopsis laurina WATER GUM None None None

Tupidanthus calyptratus TUPIDANTHUS Regular Regular Regular

Ulmus parvifolia CHINESE ELM Regular Regular Regular

Ulmus parvifolia 'Drake' DRAKE ELM Regular Regular Regular

Ulmus pumila SIBERIAN ELM Regular Regular Regular

Umbellularia californica CALIFORNIA BAY Minimal - None Minimal - None None

Viburnum tinus LAURUSTINUS Regular Regular Regular

Washingtonia filifera CALIFORNIA FAN PALM Minimal - None Minimal - None None

Washingtonia robusta MEXICAN FAN PALM Minimal - None Minimal - None None

Wodyetia bifurcata FOXTAIL PALM Moderate - Regular Moderate - Regular Moderate - Re

Xylosma congestum XYLOSMA Moderate Moderate Moderate

Yucca elephantipes GIANT YUCCA Minimal - None Minimal - None None

Yucca gloriosa SPANISH DAGGER Minimal - None Minimal - None None

Yucca spp. YUCCA Minimal - None Minimal - None None


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Department of Public Works

1685 Main StreetSanta Monica CA 90401

Parkway Landscaping Policy for the City of Santa Monica Rev 6: 02/01/10

1. Background

Parkways, the area between the outside edge of the sidewalk and the inside edge of thecurb (if any), are a component of the Public Right of Way (PROW). The City is required toregulate activities within the PROW such as telephone equipment, street lighting, bus stopsand parking meters. Adjacent property owners are required to maintain parkways ingood order according to the Santa Monica Municipal Code and other City policies.

Parkways present a number of challenges. There are issues of personal safety, vehiclesafety, efficient access for pedestrians and vehicles and resource conservation.

The purpose of this document is to establish a City policy on landscaping within parkwaysthat takes into consideration these, sometimes competing, interests while allowing propertyowners to create attractive, useful frontages.

2. ApplicabilityThis policy applies to new construction of any type in all parkways of the City of SantaMonica. For the purposes of this Policy new construction is defined as modification orimprovement of landscaping and/or irrigation, in 50% or more of the parkway area

exclusive of tree roots and existing accessways (carriage walks).

3. PermitsAn Encroachment Permit from theAdministrative Services Division of the Citys Environmentaland Public Works Management Department is required for demolition and/or constructionof any kind in parkways of the City with the exception of the installation of unirrigated,walkable plant materials such as those described in Appendix B. Permits and planapprovals issued by the Division of Building and Safety are not applicable to parkways.

4. Basic Recommended Approach

Attractive landscaping using a mixture of permeable paving and climate-appropriateplants that provides vehicle operators safe access to and from off-street parking andpedestrians safe use of the sidewalk as well as access to and from vehicles parked at thecurb. This landscaping should require little or no irrigation and produce no runoff.

5. SafetyParkway landscaping must not create visual obstructions for pedestrians or drivers ofvehicles. See Santa Monica Municipal Code (SMMC) Section 9.04.10.02.090 for specificcriteria.

Attachment 2: Parkway Policy


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Parkway Landscaping Policy Revision 6: 02/01/10 2

6.Step-Out StripsA step-out strip (a uniform, firm walking surface from the curb edge inward) must beprovided for passengers to enter and exit vehicles parked at the curb. Step-out strips mustbe at least 18 inches in width and at least 36" long, provide a firm, uniform walking

surface in all weather conditions and extend the full length of the parkway.Exception: Step-out strips are not permitted adjacent to red curbs or where roots ofexisting street trees make construction of a step-out strip with the required dimensionsimpossible or impractical (See Section 11).

Additional step-out strips may be provided adjacent to driveway aprons as desired.

7.Accessways (Carriage Walks)

If desired, the landscape design of a parkway may include an accessway for the purposeof pedestrian access to vehicles parked at the curb. If included, accessways must be atleast four feet in width and provide a firm, uniform walking surface in all weatherconditions from the curb to the sidewalk. Exception: Accessways are not permitted adjacentto red curbs or where construction of the accessway would damage or negatively impactthe roots of existing street trees. (See Section 11).

8. Areas of Limited AccessAll portions of the parkway other than step-out-strips and accessways are considered Areasof Limited Access (ALA). Landscaping in ALAs may be composed of plant material or otherfeatures except where construction of such features would damage or negatively impactthe roots of existing street trees. (See Section 11).

Figure 1 - Parkway Components


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9. Construction Criteria

A. Step-Out Strips and AccesswaysStep-out strips and accessways may be constructed of pavement, or plantmaterial*. Permeable paving such as unstabilized decomposed granite (DG) is

preferred. Stabilized DG, if used, will not be considered permeable in parkwaysgoverned by this policy. Any form of DG, if used, must be constructed according toAppendix A.

B.Areas of Limited AccessALAs may include trees** and other materials such permeable paving, boulders orconstructed objects and plants; not to exceed 34 inches in height. Native and/orMediterranean plants requiring little or no irrigation are preferred. See SMMC9.04.10.02.090 for specific criteria on plant placement and dimensions. A 2" to 4"

layer of organic mulch is recommended in planting beds and under trees. Morethan four inches may inhibit the growth of plants and street trees. To avoid harm tostreet trees, do not place mulch within 24 inches of tree trunks. See SMMC9.04.10.02.090 for criteria on placement and dimensions of landscape features.

C. Grading and DrainageThere must be no difference in grade where pavement within parkways meetsadjacent surfaces such as the curb top, sidewalk or driveway apron. Gradechanges on step-out strips are limited to per foot. Grade changes on

accesswaysare limited to per foot or the difference in elevation between thesidewalk and the top of the curb. If impermeable surfaces are used withinparkways, they must be constructed to drain to permeable areas.

* See Appendix B for a list of suggested plants. Use of plants on this list is not required.NOTE: Irrigation restrictions may influence your plant choices. See Section 10 below.

** Trees in Santa Monica's parkways are under the supervision of the City's CommunityForester. Before adding or modifying trees in the parkway, review the Citys CommunityForest Management Plan at http://www.smgov.net/Trees/Mgmt Plan/Complete.pdf orcall the Community Forester at 310/458-8974.

10. IrrigationPermanently installed irrigation of plant material in parkways is not required. Low-volume,non-spray irrigation systems or hand-watering is preferred where irrigation is needed.

Irrigation systems in parkways must be designed and constructed in a manner tocompletely preclude overspray and runoff onto any impermeable surface, public orprivate, under any condition with no exception for the effects of wind. See SMMC7.16.020 c3 & 7.10.040 a1and SMMC 8.108 Subpart B.
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No spray irrigation device of any type may be installed within 24 of any impermeablesurface or trees. See Figure 2, below.

The planned coverage area of spray irrigation systems in parkways may not include anyarea within 24 of any impermeable surface or trees. See Figure 2, below.

All irrigation equipment in parkways including heads, valves, piping, tubing and control wire

must be installed in accordance with SMMC 8.32 and SMMC 8.108 Subpart B.

When installing an irrigation system, it is important not to damage the roots of any existingstreet trees. In some cases the roots of a street tree may occupy all or a large portion of theparkway making installation of an irrigation system impractical. See example below.

Figure 2Limits of Sprinkler Irrigation in Parkways

11. Street TreesLandscaping and irrigation in parkways must be designed in a manner that does notendanger the health of existing street trees. The layout of step-out strips and accessways inparticular must be constructed in a manner that avoids interference with the existing trunkflare or roots of these trees. See examples in Figures 39 below.

It is important to understand that,in some cases, surface roots of street trees may makelandscaping, accessways, step-out strips and/or irrigation impractical or even impossible.When in doubt, review the Citys Community Forest Management Plan athttp://www.smgov.net/Trees/Mgmt Plan/Complete.pdf or contact the Community Forester.

In some cases the roots of astreet tree may occupy theentire parkway precluding theinstallation of an irrigationsystem. Landscaping orirrigation in the parkway

shown at left would bedetrimental to the tree.

Figure 3Parkway width in relation to street trees

24

24

24
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Exposed roots at the edge ofparkway preclude installation

of a Step-out strip or accessway.

Step-out strip does not

interfere with tree.

Figure 4Step-out strip in relation to tree

Figure 5Step-out strip in relation to tree roots


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24 Maintain a clear zone of at least 24around the base of the trunk to avoid

crown rot and damage from line trimmers

Figure 6Above-grade roots

Figure 7Clearance from trees

The irregular root systems found above the soilsurface in some parkways are crucial to treestability and provide limited areas for step-outstrips. An accessway would not be permitted here.


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Figure 8 Do not plant shrubsand flowers around the base oftrees. They rob newly plantedtrees of nutrients and moisture.Plants that surround the trunkflare of mature trees createconditions for crown rot which canultimately lead to the decline andfailure of the tree.

Figure 9 The photo above shows aneffective use of mulch with no plantsat the base of the trunk of the tree.

12. Maintenance ResponsibilityMaintenance of parkways is the responsibility of the adjacent property owner. See SMMC9.04.10.04.100j.

13. For questions regarding:

Plan review and permits for parkways: Contact Public Works Administrative Services [email protected] 310 / 458-8737

Landscaping and irrigation in parkways: Contact the Office of Sustainability and theEnvironment [email protected] 310 / 458-8972

Trees in parkways: Contact the Citys Community Forester [email protected] 310 / 458-8974
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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Appendix ASpecification for Installation of Unstabilized Decomposed Granite (DG) Paving

MATERIALSBase Course Aggregate:

ASTM C33, crushed stone or crushed gravel.

Decomposed Granite:1. Clean, hard, durable particles or fragments of minus fines, select brown/graycrushed granite, river rock or basalt. Fines shall be evenly mixed throughout theaggregate. When produced from gravel, 50 percent, by weight, of the material retainedon a No. 4 sieve shall have one fractured face. Color to be California Gold, Brimstone orArchitect approved equal.

2. The portion retained on the No. 4 sieve shall have a maximum percentage of wear of50 at 500 revolutions as determined by AASHTO T96-77.

3. The portion passing a No. 4 sieve shall have a maximum liquid limit of 25 and amaximum plasticity index of 7, as determined by AASHTO T89-81, and AASHTO T90-81,respectively.

4. The crushed aggregate screenings shall be free from clay lumps, vegetable matter, anddeleterious material.

PREPARATION FOR INSTALLATION

Surface Preparation:

Do necessary final excavating and filling to prepare finished subgrade. Building up ofsubgrade under forms after they are in place will not be permitted. After forms are inplace, test subgrade with template, reduce high spots to grade and raise low spots tograde with materials compacted in place by tamping.

Decomposed Granite:1. Subgrade preparation: Prior to placing the DG, shape, fill, grade, and compact thesubgrade (crushed aggregate base).

2. Forms: Install adjacent paving in lieu of forms, the full depth of decomposed granitearea, curving as required, and secure in place to hold firmly to and grade required.

If stabilizer is to be used, modify these instructions according to the manufacturersspecifications. If stabilizer is used, decomposed granite paving will be consideredan impermeable surface in parkways governed by this policy.


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Appendix A contd

INSTALLATION

Base Course1. Construct a base course layer to a depth of 4 inches (compacted). Deposit aggregatedirectly on prepared subgrade or preceding layer of compacted aggregate. Keepplaced material free from segregation. Compact each layer of material with tampingroller, with pneumatic tired roller, with vibration machine, or with combination of the three.

2. If subgrade material is worked into base course material during compacting or finishingoperations, remove base course material within affected area and replace with newaggregate. Restrict hauling over completed or partially completed work when subgrade issoft or there is tendency for subgrade material to work into base course material.

3. Compact each layer with aid of water. Provide sufficient moisture to prevent

segregation into pockets of fine and coarse material.

Decomposed Granite (DG)1. Place the DG on the prepared subgrade, in one layer of three inches minimum thicknessand rake smooth using a steel tine rake to desired grade and cross section. Do not applyDG deeper than 3 inches.

2. Water to achieve full depth moisture penetration. Watering is best accomplished usinga garden hose with spray nozzle set to a coarse spray; pressure should not disturb leveledsurface. It is essential that the full depth of water penetration by random inspection ofcores. After inspection, fill core holes with material removed, smooth and hand tamp tomatch adjoining trail surface grade. Let watered mix stand 6 to 24 hours until surface

water is no longer present; the mix should then be moist but not wet.

3. While the mix is still thoroughly moist, roll with a heavy lawn roller (minimum 225pounds and maximum 30-inch width), to achieve finish grade and initial compaction. Handtamp edges around poles, and other objects. Use a heavy (1 ton minimum) small rider,after having initially used the lawn roller, to obtain the desired final dense, smooth,uniform texture. Do not use wackers or vibratory rollers; the mix will not harden for weeksafter vibration.

4. Landscape header or curb is to remain in place, secured to hold firmly to approved lineand grade. After finished compacted surface has been achieved, finish adjacent shouldersby backfilling required grade and cross section.

INSPECTION1. Finished surface shall be smooth and uniform with no evidence of chipping or cracking.Dried, compacted material shall be firm all the way through with no spongy areas.

2. Significant irregularities shall be smoothed out prior to final acceptance of work.Smoothing shall be accomplished by rewetting/saturating rough areas thoroughly, andthen rolling the surface again with a heavy roller (1,000 to 1,500 lbs powered walk-behind or small rider). Wackers are not recommended.


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3. Final thickness of completed area shall not vary more than inch from dimensionindicated. Measurements may be taken by means of test holes taken at random in thefinished surface. Correct any variations in the thickness beyond the allowable inch byrepeating the procedures listed above.

Appendix BSuggested Plants

Use of plants on this list is not required.

Plants for Accessways and Step-Out Strips

Dymondia margaretae

Plants for Areas of Limited Access

Carex spp.

Also seehttp://www.bewaterwise.com/Gardensoft/browser01.aspxAlso go to http://www.sustainablesm.org/landscape look under Plants and

Soil See the Lawn Alternatives document
http://www.bewaterwise.com/Gardensoft/browser01.aspxhttp://www.bewaterwise.com/Gardensoft/browser01.aspxhttp://www.bewaterwise.com/Gardensoft/browser01.aspxhttp://www.sustainablesm.org/landscapehttp://www.sustainablesm.org/landscapehttp://www.sustainablesm.org/landscapehttp://www.bewaterwise.com/Gardensoft/browser01.aspx

Documents

Watering Street Trees