Parking Lt Landscaping & PlantsMEMORANDUM
April 1, 2003
TO:The Honorable Mayor and City Council Members
FROM:Michael C. Van Milligen, City Manager
SUBJECT:Parking Lot Landscaping Guidelines and Recommended Plant Lists
The Port of Dubuque Design Standards include standards, a recommended plant list,
and a visual design vocabulary for parking lot landscaping. In applying these standards,
the Port of Dubuque Design Review Committee has found that additional information
about proper planting methods and a longer list of recommended plants would be
beneficial in working with existing businesses and new developers in the Port.
The Design Review Committee recommends City Council approval of the Parking Lot
Landscaping Guidelines and Recommended Plant Lists.
I concur with the recommendation and respectfully request Mayor and City Council
approval.
MCVM/jh
Attachment
cc: Barry Lindahl, Corporation Counsel
Cindy Steinhauser, Assistant City Manager
Laura Carstens, Planning Services Manager
MEMORANDUM
March 26, 2003
To:Michael Van Milligen, City Manager
From:Laura Carstens, Planning Services Manager
Subject:Parking Lot Landscaping Guidelines and Recommended Plant Lists
The Port of Dubuque Design Standards includes standards, a recommended plant list,
and a visual design vocabulary for parking lot landscaping. In applying these standards,
the Port of Dubuque Design Review Committee has found that additional information
about proper planting methods and a longer list of recommended plants would be
beneficial in working with existing businesses and new developers in the Port.
The Port of Dubuque Design Review Committee has reviewed the enclosed Parking Lot
Landscaping Guidelines and Recommended Plant Lists prepared by City Forester
Steve Pregler and architect Steve Ulstad, who has developed the parking lot
landscaping for the Grand Harbor Resort and Waterpark and the Grand River Center.
The current Recommended Plant List is enclosed, which you can see is fairly short.
The Committee believes that the expanded Parking Lot Landscaping Guidelines and
Recommended Plant Lists will be a useful supplement to the Port of Dubuque Design
Standards.
The Committee recommends City Council approval of the Parking Lot Landscaping
Guidelines and Recommended Plant Lists. If approved, the expanded Parking Lot
Landscaping Guidelines and Recommended Plant Lists will be added to the Appendix
of the Design Standards in place of the existing Recommended Plant List.
Enclosures
CC Pauline Joyce, Administrative Services Manager
Cindy Steinhauser, Assistant City Manager
Icarsten/Arnedca's River/Port of DubuquetParldng Lot Landscaping/memo mvrn landscaping guidelines.doc
Existing Appendix
Bibliography
Bart Eoglneeflng Company. 2001, Mbmesota Urban Small Sites
BMP Manual; Stormwater best l~],anagement practices for coM
climates. Metropotitao Council En~iroomenta] Services. Available
from the Metropolitan Council at 651-§02~ lBO0 or
www. metrocounalLo~g.
Claytor, Ric?rd A. oald Thomas E. Scbueler, 199ti. Design of
Stormwater FtlterbLg Systems. Chesapeake Research Consorgum.
Available from The~entar for Watershed Protection at 41g-4tit~
8323
Minnesota Potiution Control Agency. 2000. Protecting Water
Quality in Urban Areas; tiest management practices for dealing
with stona water ruuoff from urban, suburb~h and developing
areas in Minnesota. Mionesota Pollution Control Agency.
Available from tire MPCA contact Mary Osborn at
051~296-7523
Pre-Development Temporary Fencing
The foBowing products are pre-approved by tile City for use at
the Port of Dubuque; however,~It shall ,b.e understood that B~e
Adllesfen: HF-weldabfe.
Recommended Plant List
Res
Auturon Blaze Maple
River Birch
IIacbhar
Marallallr~eedless Ash
Acer x fieemanti 'Jeffma Red'
Betula nigra
Ualtis accldentalts
Fraxinus pennsylvanica 'Marsball~
Seedless'
Shrubs
Black Cbokeberrry* Aronia metanocarpa
Isanti Dogwood* Comus sericea 'lsanfi'
Sroooth Wild Rose Rosa blonds
Meadowsweet Spiraea alba
Westarn Snowberry Sympboricarpos occidealtalls
Grasses
tiebb's Sedge Corex bebbti
FOX Sedge Carex vu~inoidea
Soft Rush Juneus ellUSLL~
Torroy Rush Juncos torreyt
Little Blueslem Schizachyciuro scoparium
Prairie Dropseed SporoboI~ hete~lepis
Ftowl3r$
Yarrow Achitiea 'Moonshine'
Marsh Milkweed Asclepiasincarnata ,
Alert Red Aster Aster novi-belgll 'Alert
New England Aster * Aster novae-angliae
Joe Pye Weed * Eupatorlum roaculatum
Meadow Blazing Star Liatsb tigulls~lis
Great Blue Lob~ia Lobetia siphibtica,
Bee Balm Monarda didyma Marsbatis
Obedient Plant Delight'
Black Eyed Susan Ph~sostegla vlr$iniana
Splderwort RudbeekTa fulg~da 'Goldsturm
Culver~ Root* Tradescantia oJtlansis
Golden Alexanders Veronicastrum vlrginicum
Zizla aurea
* Hams that should be reserved for buffer and scree.log areas
because they grow over 3 feet in beigbt and may btiLibR surveglance,
Streetscape Furnishings List
Tile following products are preapproved by lhe City for use at die
Port of Dubuque; however, it shall be understood tilat file items
listed are all subject to all ~or equal~ review process. Product
substitutions of equal design, qualily and performance are
permissable per the review and approval of tile City.
Cafe Table: 'Steelhead' 3g' table lop with "Corona" surface mount
base, Grottopowdercoat, Landscape Forms Kalamazoo, ML
lumfealre by Garden CA 22 Style with minimum 250 w.aR Metal
powdercoat RAL 9017 (b ack) sesooth gloss finish.
PARKING LOT LANDSCAPING GUIDELINES
Trees and other various landscape plants can be used to fulfill specific landscape
functions and be aesthetically pleasing when placed in parking lot planters and
medians.
Urban parking lots are harsh environments for trees and other landscape plants. They
are subject to limited soil volumes, reflected heat and light from the pavement,
automobile exhaust fumes, soil contaminants and mechanical injury.
To ensure the success of parking lot landscape plantings, trees in particular, a favorable
soil environment is critical. The soil environment must have sufficient open surface area
for replenishment of oxygen, water and mineral elements; and an adequate soil volume
to hold and provide all of these essential resources necessary for healthy root growth.
Without them, the plants will slowly decline and die.
Tree performance and longevity are directly related to the soil quality and volume
provided them. For trees, soil volume is critical because it must be able to hold and
supply adequate moisture to meet the trees increased transpiration needs, due to the
parking lot heat island effect. Medium sized trees require 600-1,000 cubic feet of soil to
grow with a lower risk of environmental stress and have a more reasonable longevity.
Soil quality is also critical. A friable clay loam soil provides aeration, allowing oxygen to
the roots; adequate water holding capacity but well drained; and a supply of the thirteen
essential mineral elements required for plant growth. Healthy soils also contain a
multitude of beneficial soil microorganisms, which form a symbiotic relationship with the
plants.
With good soils, tree selection is not a hit and miss proposition. Disturbed or man-made
soils that are frequently encountered in parking lot plants do not exist in nature; thus, it
is not entirely possible to select a tree genetically adept to these disturbed soil types.
The perfect tree: one that is flood tolerant, drought resistant and able to adept to poor
soil conditions and a number of other desirable attributes, does not exist. Favorable
parking lot trees are trees we call pioneer trees. Pioneer trees, in nature, are the first
ones to establish in the open prairie where conditions are often as harsh as those found
in a parking lot.
Planting Guidelines
A raised planter, sidewalk planting pit or planting median should be designed to hold an
adequate soil volume for the size tree or trees selected (600 - 1,000 cubic feet per
medium size tree). Maximize the soils open surface area whenever possible.
Raised beds in a median or island planter provide additional soil volume and open
surface area. Medians or island planters should be a minimum of 10 feet wide.
A minimum depth of 36 inches of soil should be used when figuring soil volumes for
raised planters and sidewalk planting pits, and a 24-inch depth for planting medians.
A typical island or median planter might measure 10 feet by 30 feet by 2 feet. A typical
raised planter might measures 10 feet by 20 feet by 3 feet.
A typical sidewalk planting pit or vault might measure 6 feet by 6 feet at the grate
opening, but the vault beneath the sidewalk might measure 10 feet by 20 feet by 3 feet
for a single tree. Linear street side plantings might share a single vault 10 feet wide by
3 feet deep that runs the entire length of the city block beneath the sidewalk.
Raised planters, sidewalk plantings pits and planting medians should be designed to
provide adequate water drainage away from the effective root area. This can be
accomplished using perforated PVC pipe in a gravel bed, protected from silt with a
geotextile covering.
NOTE: Many variations in planter design exist. Most planters will be designed for the
particular site. Four key elements must be met: (1) Adequate soil volume, (2) Adequate
open surface area, (3) Adequate drainage, and (4) Quality topsoil.
A friable clay loam topsoil with a 4-6% organic matter content should be used as the
primary planting medium. The soil should be relatively free of stones and other debris.
In most instances, small and medium sized trees will be most appropriate for parking lot
plantings. When trees or other plant materials are planted in medians that are
perpendicular to the parking stalls, they should be placed a minimum of four feet behind
the curb. Follow the latest tree planting recommendations for successful planting as
outlined in the Sample Planting Specifications for Trees by Edward F. Gillman.
Carefully remove wire baskets from the tree's root ball. Planting depth is critical. Make
sure that the root crown is visible at the top of the root ball. Place the root ball in the
planting hole so that the root crown is level with or above grade. The rope and 1/3 of
the burlap should be cut away at the top of the root ball before you finish backfilling.
All tree and parking lot landscape plantings should be mulched with organic mulch, such
as shredded bark or wood chips; 2-3 inches deep. Mulch should not come in contact
with the tree's trunk. (Trees and turf do not compete well together; therefore turf is not
recommended as a landscape groundcover around plantings.)
Not all geotextile fabrics are created equal. Their effectiveness varies, depending upon
their porosity. The less porous the material, the more effective it is as a weed barrier
and barrier to the free movement of water and oxygen to the soil. The use of geotextile
fabrics is not recommended.
Proper Tree Planting Diagram
.Remove transit guard~
Remove wire baskets:~
~ro cbt top and fold
wn in the after
~ositioned
airway. Cut and fold
down burlap from
upf~er 1/2 of bali.
Cbt and remove all
poly ties.
2 - 4" Of woody
mulch:Aged wood
chips, §i~redde, d bark,
or similar mulch. Keep-~
mulch 6" back from
trunk.
Branching:Low Branches
are but alp
or '
or
double leaders at
planting time.
graft
Root collar shall be
-level or up to ~ - 2"
above fin~shed grade.
-Remove excess soil from
top of bail if needed.
Grade
Bacfftfll:
Use existing
soil Water
tehflmgrq, ug. hly to
Inane air
pockets. Do
not tamp!
Soil under ball undisturbed
to support root ball and
reduce settling
3 tfmes ball diameter ·
Break down
sides of the
hole when
ba clcElling
Stake only if you have to. Use 2-3';wide webbing straps and secure to stakes with
heavy gauge wire. The wire should be able to stick straight out from the stake and
hold the webbing strap up, preventing it from sliding down the tree. Do not stake
tightly - trees gain strength from movement. Remove all stakes after one year.
Use of tree wrap is not recommended, as it causes a number of problems for the tree.
Wisconsin Dept. Of Natural Resources - Oct. 2000
RECOMMENDED PLANT LISTS
Below are the recommended plant lists of trees, shrubs, grasses and perennials that are
suitable for parking lot landscape plantings. The lists include common name, scientific
name, and variety (if any).
Deciduous Trees
Large Trees (40'- 60')
Freeman Maple
Norway Maple
River Birch
Hackberry
Ginkgo
Honey Locust
Little Leaf Linden
Swamp White Oak
Bur Oak
Red Oak
Green Ash
Acer freemanii
Acer platanoides
Betula nigra
Celtis occidentalis
Ginkgo biloba
Gleditsia tricanthos inermis
Tilia cordata
Quercus bicolor
Quercus macrocarpa
Quercus rubra
Fraxinus pennsylvanica
Autumn Blaze
Emerald Queen, Easy Street*
Moraine, Shademaster, Skyline
Glenleven
Patmore, Prairie Spire, Summit*,
Marshall's Seedless Ash
Medium Trees (35'-40')
Norway Maple Acerplatanoides
Honey Locust Gledtisia tricanthos inermis
Ornamental Pear Pyrus callerana
Big Leaf Linden Ti/ia Americana
Columnar*, Parkway*
Imperial, True Shade
Aristocrat*, Autumn Blaze,
Chanticeleer*, Red Spire
Redmond*
Small Trees (15'-35')
Norway Maple
Hybrid Maple
Thomless Hawthorn
Hawthorn
Little Leaf Linden
Red Bud
Pagoda Dogwood
Sargent Cherry
Ornamental Crabapple
Acer platanoides
Acer truncatum xA. Platanoides
Cratagus crusgalli inermis
Cratagus crusgalli x lavallei
Ti/ia Cordata
Cersis Canadensis
Cornus alferifolia
Prunus eargentii
Malus (various)
Crimson Sentry*
Pacific Sunset*
Cockspur
Lavalle
Chancellor*
Adirondak*, Centurion*,
Lisit*,Golden Raindrops*,
Sentinel*, Harvest Gold*,
Spring Snow Crab
*Indicates a more upright form
Ever.qreen Trees
Large Trees (50')
Norway Spruce
Black Hills Spruce
Medium Trees (25-30')
Eastern Red Cedar
American Arborvitae
Small Trees (10'-15')
Chinese Upright Juniper
Upright Junipers
Arborvitae
Picea abies
Picea glauca
Juniperus virginiana
Thuja occidentalis
Juniperus chinensis
Juniperus scopulorum
Thuja occidentalis
Hetz Columnar, Mountbatten
Blue Haven, Medora,
Wichita Blue
Techny, Woodward,
Emerald Green
Shrubs
Evergreen Shrubs
Creeping Juniper
Spreading Juniper
Mugho Pine
Arborvitae
Flowering Shrubs
Burning Bush
Honeysuckle
Potenttilla
Weigela
Black Chokeberry**
Isanti Dogwood**
Smooth Wild Rose
Western Snowberry
Shasta Viburnum**
Viburnum**
Cranberry Bush**
Spirea
Juniperus horizontalis
Juniperus chinensis
Pinus mugo
Thuja occidentalis
Euonymus alta compacta
Lonicera x xylosteoides
Potentilla fruticosa
Weigela florida
Aronia melanocarpa
Comus serices 'lsanti'
Rosa blanda
Symphoricarpos occidentalis
Viburnum plicatum shasta
Viburnum dentatum
Viburnum trilobum
Spiraea x bulmada
Andorra, Blue Rug, Hughes
Pfitzer, Sargent Blue, Sea Green
Hetz Midget, Woodward
Spirea Spiraea x japonica
Spirea Spirea a/ba
Dwarf Burning Bush
Clavey's Dwarf
Gold Drop
Red Prince
Chicago Lustre
Compact American
Anthony Waterer,
Goldflame, Goldmound
Little Princess
Meadowsweet
**Plants that should be reserved for buffer and screening areas because they grow over
3 feet in height and may inhibit surveillance.
Grasses
Bebb's Sedge
Fox Sedge
Soft Rush
Torrey Rush
Little Bluestem
Prairie Dropseed
Feather Reed Grass
Blue Lyme Grass
Silver Grass
Fountain Grass
Carex bebb#
Carex vulpinoidea
Juncus effuses
Juncus torreyi
Schizachyrium scoparium
Sporobolus heterolepis
Calamogrostis x acutiflora
Elymus arenarius
Miscanthus sinensis
Pennisetum alopecurolder
Karl Foerster
Morning Lights
Perennials
Yarrow
Marsh Milkweed
Red Aster
New England Aster**
Joe Pye Weed**
Meadow Blazing Star
Great Blue Lobelia
Bee Balm
Obedient Plant
Black Eyed Susan
Spiderwort
Culver's Root**
Golden Alexanders
Happy Returns
Purple Coneflower
Shasta Daisy
Daffodils
Ach#lea
Ascepias incarnate
Aster novi-belgii
Aster novae-angliae
Eupatorium maculatum
Liatds ligulistylis
Lobelia siphilitica
Monarda didyma
Physostegia virginiana
Rudbeckia fulgidia
Tradescantia ohiensis
Veronicastrum virginicum
Zizia aurea
Hemerocallis
Echinacea purpurea
Chrysanthemum
Narcissi
Moonshine, Coronation Gold
Alert
Marshall's Delight
Goldstrum
Superbum Becky
Show & Naturalizing
**Plants that should be reserved for buffer and screening areas because they grow over
3 feet in height and may inhibit surveillance,