The purposes of this subchapter are:
A. 
To enhance the visual continuity within and between neighborhoods.
B. 
To establish at least an urban tree canopy through landscaping and street trees.
C. 
To screen areas of low visual interests and buffer potentially incompatible developments.
D. 
To complement the site and building design with landscaping.
(Ord. 238 Ch. V § 7(A), 2000; Ord. 907 § 1 (Exh. A), 2020)
A. 
Type I landscaping is a “full screen” that functions as a visual barrier. Type I landscaping shall minimally consist of:
1. 
A mix of primarily evergreen trees and shrubs generally interspersed throughout the land-scaped strip and spaced to form a continuous screen.
2. 
Eighty percent of trees and shrubs shall be evergreen.
3. 
Trees planted at 10 feet in height, at the rate of one tree per 10 linear feet of landscaped strip and spaced no more than 15 feet apart.
4. 
Shrubs planted from five-gallon containers or at 30 inches in height and spaced no more than three feet apart on center.
5. 
Ground covers planted from minimally four-inch pots and spaced no more than 18 inches apart.
B. 
Type II landscaping is a “filtered screen” that functions as a partial visual separator to soften the appearance of parking areas and building elevations. Type II landscaping shall minimally consist of:
1. 
Trees generally interspersed throughout the landscaped strip and spaced to create a continuous canopy.
2. 
Provide a mix of deciduous and evergreen trees and shrubs.
3. 
Trees planted at 1.5-inch caliper, at the rate of one per 25 linear feet of landscaped strip and spaced no more than 30 feet apart on center.
4. 
Shrubs planted from five-gallon containers or at 24 inches in height and spaced no more than four feet apart on center.
5. 
Ground covers planted from minimally four-inch pots and spaced no more than 18 inches apart.
C. 
Existing, healthy trees and shrubs, vegetated critical areas, landscaped bio-swales, or trees and their area within the dripline may substitute for required landscaping tree-for-tree and area-for-area. In order to promote the retention of existing mature trees during site development, credit shall be given for one additional required tree if the retained tree is significant. (See Subchapter 5 of this chapter, Tree Conservation, Land Clearing, and Site Grading Standards, and Chapter 20.80 SMC, Critical Areas, for additional requirements).
(Ord. 238 Ch. V § 7(B-1), 2000; Ord. 1027 § 1 (Exh. A), 2025)
A. 
Provide a five-foot-wide, Type II landscaping that incorporates a continuous masonry wall between three and four feet in height. The landscape shall be located between the public sidewalk or residential units and the wall; or
B. 
Provide at least 10-foot-wide, Type II landscaping.
C. 
All parking lots shall be separated from ground-level, residential development by the required setback and planted with Type I landscaping.
20.50.470(A) Parking lot planting buffer with low wall
20.50.470(B) 10-foot parking lot buffer with Type II landscaping
D. 
Vehicle Display Areas Landscaping. Shall be determined by the Director through administrative design review under SMC § 20.30.297. Subject to the Director’s discretion to reduce or vary the depth, landscaped areas shall be at least 10 feet deep relative to the front property line. Vehicle display areas shall be framed by appropriate landscape materials along the front property line. While allowing the vehicles on display to remain plainly visible from the public rights-of-way, these materials shall be configured to create a clear visual break between the hardscape in the public rights-of-way and the hardscape of the vehicle display area. Appropriate landscape construction materials shall include any combination of low (three feet or less in height) walls or earthen berms with ground cover, shrubs, trees, trellises, or arbors.
(Ord. 238 Ch. V § 7(B-2), 2000; Ord. 560 § 4 (Exh. A), 2009; Ord. 581 § 1 (Exh. 1), 2010; Ord. 654 § 1 (Exh. 1), 2013; Ord. 789 § 1 (Exh. A), 2018)
A. 
When frontage improvements are required by Chapter 20.70 SMC, street trees are required for all commercial, office, public facilities, industrial, multifamily developments, and for residential developments on all arterial streets.
B. 
Frontage landscaping may be placed within City street rights-of-way subject to review and approval by the Director. Adequate space should be maintained along the street line to replant the required landscaping should subsequent street improvements require the removal of landscaping within the rights-of-way.
C. 
Street trees and landscaping must meet the standards for the specific street classification abutting the property as depicted in the Engineering Development Guide including but not limited to size, spacing, and site distance. All street trees must be selected from the City-approved street tree list.
(Ord. 238 Ch. V § 7(B-3), 2000; Ord. 406 § 1, 2006; Ord. 581 § 1 (Exh. 1), 2010; Ord. 731 § 1 (Exh. A), 2015; Ord. 739 § 1 (Exh. A), 2016; Ord. 984 § 1 (Exh. A), 2023; Ord. 1027 § 1 (Exh. A), 2025)
A. 
The portion of the building adjacent to public rights-of-way shall have landscaping along the building facade. Foundation landscaping shall abut the building (while allowing the necessary space for growth) and shall be used or installed in such a manner so as to screen mechanical equipment attached to or adjacent to the building, provide direction to and enhance entrances and pedestrian pathways, and provide visual breaks along building facades.
B. 
1. 
Landscaping shall be provided at a depth of at least 50 percent of the required front yard setback. The depth of required landscaping for properties with frontage on 145th Street or 185th Street shall be calculated by subtracting the amount of right-of-way dedication easement.
2. 
If a property has a required setback of zero feet, landscaping shall be provided at a depth of at least four feet and width at least 30 percent of the unit width. The required landscaping shall abut the entry. For example, if the unit width is 20 feet, the landscaping next to the entry shall be a minimum of six feet wide.
C. 
Foundation plantings may be comprised of trees, shrubs, accent plants, ornamental grasses, and ground cover in any combination; provided, that no more than 50 percent of the total required landscaping area consists of ground cover.
D. 
At least one three-gallon shrub for every three lineal feet of foundation shall be provided.
E. 
Shrubs shall be a mix of deciduous and evergreens.
F. 
When calculating the minimum number of required plants, the linear distance of openings for doors entering the building shall be excluded.
Front Facade Landscaping Illustrations
(Ord. 871 § 1 (Exh. A), 2020)
A. 
Type I landscaping in a width determined by the setback requirement shall be included in all nonresidential development along any portion adjacent to residential development. All other nonresidential development adjacent to other nonresidential development shall use Type II landscaping within the required setback. If the setback is zero feet then no landscaping is required.
B. 
Multifamily development shall use Type I landscaping when adjacent to other forms of residential development and Type II landscaping when adjacent to multifamily residential and commercial development within the required yard setback. Single-family attached and mixed single-family developments in the MUR or TC-4 zones shall use Type I landscaping when adjacent to NR zones, and Type II landscaping when adjacent to all other zoning districts. Single-family attached and mixed single-family developments that have a shared access drive with an abutting property are exempt from this requirement on the side with the shared access drive.
Single-Family Attached and Mixed Single-Family Interior Landscaping Illustration
C. 
A 20-foot width of Type I landscaping shall be provided for institutional and public facility development adjacent to residential development. Portions of the development that are unlit play-grounds, playfields, and parks are excluded.
D. 
Parking lots shall be screened from residential dwelling units by a fence, wall, plants or combination to block vehicle headlights.
Figure 20.50.490(D): Example of parking screened from single-family house.
(Ord. 238 Ch. V § 7(B-4), 2000; Ord. 299 § 1, 2002; Ord. 789 § 1 (Exh. A), 2018; Ord. 871 § 1 (Exh. A), 2020; Ord. 984 § 1 (Exh. A), 2023; Ord. 1027 § 1 (Exh. A), 2025)
Required parking area landscaping shall include landscape areas that are located in areas within or adjacent to parking areas. However, landscaping designed to meet perimeter landscaping requirements cannot also be used to meet parking lot landscaping requirements.
A. 
Multifamily developments with common parking areas shall provide planting areas in parking lots at a rate of 20 square feet per parking stall.
B. 
Commercial, office, industrial or institutional developments shall provide landscaping at a rate of:
1. 
Twenty square feet per parking stall when 10 to 30 parking stalls are provided; or
2. 
Twenty-five square feet per parking stall when 31 or more parking stalls are provided.
C. 
Trees shall be provided and distributed throughout the parking area at a rate of one tree for every 10 parking stalls.
D. 
Permanent curbs or structural barriers shall be provided to protect shrubs and trees from vehicle bumpers. Landscaping under vehicle overhang shall not be included in required landscape area calculations.
E. 
Parking area landscaping shall require:
1. 
At least 60 square feet with a lineal dimension of no less than four feet;
2. 
Shrubs planted from five-gallon containers or at 24 inches in height and spaced no more than four feet apart on center;
3. 
Ground covers planted from minimally four-inch pots and spaced no more than 18 inches apart;
4. 
Trees planted at least 1.5 inches caliper in size;
5. 
Gaps in curbs are allowed for stormwater runoff; and
6. 
Natural drainage landscapes (such as rain gardens, biofiltration swales and bioretention planters) when designed in compliance with the stormwater design manual.
(Ord. 238 Ch. V § 7(B-5), 2000; Ord. 654 § 1 (Exh. 1), 2013; Ord. 669 § 1 (Exh. A), 2013; Ord. 984 § 1 (Exh. A), 2023; Ord. 1027 § 1 (Exh. A), 2025)
Alternative landscape designs may be allowed, subject to City approval, if the design accomplishes equal or better levels of Type I or II landscaping.
A. 
The average width of the perimeter landscape area may be reduced 25 percent along interior property lines where:
1. 
Berms at least three feet in height (2:1 slope) or walls and fences at least six feet in height are incorporated into the landscape design; or
2. 
Plant material that would be required is located elsewhere on site.
B. 
When an existing structure precludes installation of the required site perimeter landscape area then the plant material shall be incorporated on another portion of the site.
(Ord. 238 Ch. V § 7(B-6), 2000)
A. 
Berms shall not exceed a slope of two horizontal feet to one vertical foot (2:1).
B. 
All new turf areas, except all-weather or sand-based athletic fields, shall be augmented with a two-inch layer of organic material cultivated a minimum of six inches deep or have an organic content of five percent or more to a depth of six inches.
C. 
Except as specifically outlined for turf areas in subsection (B) of this section, the organic content of soils in any landscape area shall be as necessary to provide adequate nutrient and moisture-retention levels for the establishment of plantings.
D. 
Landscape areas, except turf or areas of established ground cover, shall be covered with at least two inches of mulch to minimize evaporation.
E. 
Plant selection shall consider adaptability to climatic, geologic, and topographical conditions of the site. Preservation of existing vegetation is encouraged.
F. 
All plants shall conform to American Association of Nurserymen (AAN) grades and standards as published in the “American Standard for Nursery Stock” manual; provided, that existing healthy vegetation used to augment new plantings shall not be required to meet the standards of this manual.
G. 
Multiple-stemmed trees shall be permitted as an option to single-stemmed trees; provided, that such multiple-stemmed trees are at least 10 feet in height and not allowed within street rights-of-way.
H. 
When the width of any landscape strip is 20 feet or greater, the required trees shall be staggered to avoid the appearance of a single row of trees.
I. 
All fences shall be placed on the inward side of any required perimeter landscaping when adjacent to a public right-of-way and on the outward side of the required landscaping or on the property line when adjacent to private property.
J. 
Required street landscaping may be placed within Washington State rights-of-way subject to permission of the Washington State Department of Transportation.
K. 
New landscape material shall be indigenous plant species within areas of undisturbed vegetation, within critical areas or their buffers or within the protected area of significant trees; provided, that pesticide and chemical fertilizer may be restricted within these landscaped areas.
L. 
All landscaping shall be installed according to sound horticultural practices in a manner designed to encourage quick establishment and healthy plant growth. All landscaping shall either be installed or the installation shall be secured with a letter of credit, escrow, or performance bond for 125 percent of the value of the landscaping prior to the issuance of a certificate of occupancy for any building in such phase.
M. 
Trees and vegetation, fences, walls and other landscape elements shall be considered as elements of the project in the same manner as parking, building materials and other site details. The applicant, landowner or successors in interest shall be responsible for the regular maintenance of all landscaping elements in good condition.
N. 
Applicants shall provide a landscape maintenance and replacement agreement to the City prior to issuance of a certificate of occupancy.
O. 
Landscape plans and utility plans shall be coordinated. The placement of trees and large shrubs shall accommodate the location of required utilities both above and below ground. Location of plants and trees shall be based on the mature canopy and root zone. Root zone shall be determined using the International Society of Arboriculture’s recommended calculation for identifying tree protection area. Mature tree and shrub canopies may not reach an aboveground utility such as street lights and power lines. Mature tree and shrub root zones may overlap utility trenches as long as 80 percent of the root zone is unaffected.
P. 
Adjustment of plant location does not reduce the number of plants required for landscaping.
Q. 
Sight distance triangle for visual clearances shall be established and maintained. The criteria for sight distance and visual clearances are contained in and consistent with the Engineering Development Guide for all driveway exits and entrances and street corners.
(Ord. 238 Ch. V § 7(B-7), 2000; Ord. 581 § 1 (Exh. 1), 2010; Ord. 591 § 1 (Exh. A), 2010)