Chapter 19.29 LANDSCAPING

Chapter 19.29
LANDSCAPING

Sections:

19.29.010 Purpose and intent.

19.29.020 Definitions.

19.29.030 Application of chapter.

19.29.040 Exemptions.

19.29.050 Objectives.

19.29.060 Overlapping requirements.

19.29.070 Landscaping plan and submittal.

19.29.080 General provisions.

19.29.090 Area and situation-specific landscaping requirements.

19.29.100 Description of required landscaping types.

19.29.110 Protection of significant trees and existing native vegetation.

19.29.120 Installation standards.

19.29.130 Maintenance requirements.

19.29.010 Purpose and intent.

The purpose of these landscaping requirements is to establish consistent and comprehensive provisions to:

(1) Preserve and enhance the landscape character of the city;

(2) Improve the aesthetic quality of the built environment of the city;

(3) Minimize erosion and reduce the impacts of development on natural areas within the city and on storm drainage systems and water resources in particular;

(4) Protect existing street trees;

(5) Provide shade, reduce noise and glare, and establish a healthier environment;

(6) Provide transitions between various land uses;

(7) Improve and soften the appearance of parking areas;

(8) Ensure plant establishment and survival;

(9) Increase privacy and protection from visual or physical intrusion;

(10) Maintain and protect property values, and generally enhance the overall image and appearance of the city and quality of life for its citizens; and

(11) Avoid untimely and haphazard removal or destruction of significant trees and vegetation while preserving important landscape characteristics.

It is not the intent of these requirements to impose rigid and inflexible design standards, but rather to set minimum standards. It is expected that accepted horticultural practices and landscape architectural principles will be applied by design professionals. (Ord. 19-20 § 1 (Att.), 2020).

19.29.020 Definitions.

Unless noted otherwise in this chapter, the words or phrases defined in this section shall have the indicated meanings as follows:

(1) “Congruous,” for the purpose of determining buffer requirements, means:

(a) Two adjacent parcels in the same zone or like zones (e.g., adjacent zones that are primarily industrial, commercial, or residential); or

(b) A proposed use adjacent to a zone where that use is also permitted.

(2) “Adjacent” means two properties that abut or are across an alley from one another.

(3) “Diameter at breast height” (DBH) means the diameter of a tree trunk measured at four and one-half feet above grade.

(4) “Drip line boundary” is measured in two ways, depending on the growth habit of the tree. The drip line that applies is whichever of the following results in a greater distance.

For wide canopies: The drip line is measured as a line extending from the extreme reach of a tree’s branches down to the ground.

For narrow canopies: The drip line is a buffer distance extending in a circle measuring one foot in distance from the trunk for every one inch in diameter of DBH.

(5) “Height of tree” means the distance from growth stem at treetop to top of root ball.

(6) “Landscaping” means the placement, preservation, and/or replacement of trees, shrubs, plants, and other living vegetative materials installed to meet the provisions of this chapter. Bark, mulch and ornamental rock are not considered to be substitutes for living landscape plants or ground cover.

(7) “Landscaping area” means any portion of a site not used for building, parking, driveway or accessory storage area. A landscape area may include patios, plazas, walkways, walls and fences, fountains or pools, and planting areas. Ponds, streams, natural areas, or areas for the detention of stormwater runoff are not considered part of the landscaped area of a site unless they are integrated with required landscaping as a water feature.

(8) “Maintenance” means the continual maintenance of planting areas and landscape plants in a healthy, living condition; the replacement of dead, diseased, or damaged plant material; and the repair of irrigation systems.

(9) “Parking lot” means an area devoted to vehicular parking for three or more dwelling units or any commercial or industrial building.

(10) “Significant trees” means native trees having a DBH of at least 12 inches. A tree growing with multiple stems shall be considered significant if at least one of the stems, measured at a point six inches from the point where the stems digress from the main trunk, is at least four inches in diameter. Alders (Alnus rubra), cottonwoods (Populus aigeiros), and trees in the Poplar species shall not be considered a significant tree. A dead tree or a tree that has been identified by a qualified arborist as substantially diseased or damaged shall not be considered a significant tree.

(11) “Stand” means a homogenous grouping of tree species or a group of trees that contains a large proportion of the same species. (Ord. 19-20 § 1 (Att.), 2020).

19.29.030 Application of chapter.

(1) The standards required by this chapter shall apply in any of the following cases, unless otherwise noted in this chapter:

(a) All uses of land which are subject to site plan review or a shoreline permit;

(b) All final plats or short plats;

(d) Additions to existing buildings that increase the gross square footage of the building by greater than one-third;

(e) Conversion of vacant land (e.g., to parking or storage lots);

(f) Conversion of a residential use to a nonresidential use;

(g) Manufactured home parks and subdivisions, and recreational vehicle parks;

(h) New streets and street rehabilitation projects;

(i) A change of occupancy of commercial and/or manufacturing use property as defined by the International Building Code, and/or improvements of at least 50 percent of the assessed property value. (Ord. 19-20 § 1 (Att.), 2020).

19.29.040 Exemptions.

(1) The following uses are exempt from all but the maintenance and street tree requirements of this chapter:

(a) Single-family residential building permits, when not a part of a new subdivision;

(b) Duplex residential building permits, when not part of another permit process;

(d) Nonperimeter portions of vehicle sales display areas;

(e) Nonperimeter portions of storage lots; and

(f) Those alterations or small additions determined by the planning director not to warrant improvements to the entire site. (Ord. 19-20 § 1 (Att.), 2020).

19.29.050 Objectives.

(1) Provide building facade buffers to produce a softening effect to new buildings or developments as well as encourage landscaping by current merchants.

(2) Provide sight and noise barrier buffers between incongruous land uses, e.g., between residential and commercial uses.

(3) Provide and maintain natural riparian corridors along streams, wetlands and drainage areas.

(4) Provide visual screening around dumpster areas and utility boxes.

(5) Ensure that the following landscaping maintenance done by the city of Buckley is minimized:

(a) Cleaning of drains from leaves and other yard waste clutter.

(b) Pruning required allowing emergency vehicles easy access along streets.

19.29.060 Overlapping requirements.

In the event of a conflict between the standards for individual uses and other requirements of this chapter, the more stringent shall apply. Determination of the appropriate standards shall be made by the planning director. In the event of a conflict between the standards for individual uses and other general requirements of this chapter with the requirements of the shoreline master program (SMP), the requirements of the SMP shall apply. Landscaping regulations shall not be construed as conflicting with SMP regulations where they supplement SMP standards rather than replace them. For example, if the zoning code imposes a wider landscape buffer than the SMP buffer, the wider zoning code buffer shall apply. However, if the SMP requires specific vegetation within the buffer, then SMP requirements shall apply. (Ord. 19-20 § 1 (Att.), 2020).

19.29.070 Landscaping plan and submittal.

(1) Submittal Requirements.

(a) Preliminary Plans. The conceptual preliminary landscaping plan, drawn to scale, shall be submitted with the development application for all projects specified in BMC 19.29.030, Application of chapter. The preliminary plan shall indicate existing and proposed plant material. The preliminary landscaping plan shall be submitted in a digital format. The planning director may request hard copies; the number of copies shall be prescribed by the planning department.

(b) Final Plans. The final landscape plan drawn to scale shall be submitted with the building permit application and site plan for any project referenced under BMC 19.29.030, Application of chapter. No clearing, grading or building permit will be issued before the submittal of this final plan. The final landscaping plan should encourage a low maintenance, quality design. Design with drought-resistant plants and minimal grass area is encouraged to promote water conservation. Design shall include utilization of native vegetation.

The final plan submission must include:

(i) Location. Provide legal description of site or parcel as well as name and address of owner and/or developer when different from the owner.

(ii) Planting Schedule. The planting schedule shall indicate common names, quantities, sizes at planting, and spacing for all plants. The final site plan will show individual trees and shrubs. Ground cover may be expressed as on-center (o.c.) placement.

(iii) Cost Estimate. If a performance assurance is proposed as an alternative, the applicant must submit a current estimate of the cost to install the required landscaping. The planning director may approve the submitted cost estimate or require that written bids be obtained.

(iv) Elevation Drawing. An elevation and/or cross-section drawing is required for steep slopes that exceed five feet in height and are steeper than one unit vertical in one and one-half units horizontal (1:1.5). The scale should be appropriate to show structures and plantings at time of installation.

(v) Grading Details. If land contours are to be altered, existing and proposed grading contours with spot elevations shall be drawn to scale on the preliminary and final site or landscape plan. All landscaped mounds, ditches, and gullies are to be shown.

(vi) Existing Tree Survey. Applicants shall submit a tree survey indicating the name, caliper, and location of any existing tree greater than six inches in caliper at four and one-half feet above grade. The boundaries and species of any stands of trees shall be detailed. The plan shall note which trees shall be retained, using the drip line boundary delineation to locate retained trees on the grading plan. An effort shall be made to preserve existing trees, especially conifers, on site and incorporate them into overall design.

(c) Revisions. A revised landscaping plan may be approved by the planning director in the event there are significant physical elements which are discovered during or after plan review which may prevent installation of the required landscaping. Revisions to the approved landscaping plan may be required if the installed landscaping has failed to perform as intended during the maintenance warranty period.

(2) Performance Assurance. Before the issuance of a certificate of occupancy for any project is issued, the approved landscaping must be installed, unless the developer provides a performance security to guarantee the installation of the landscaping. The amount of the security will be based on 150 percent of the projected cost to install the approved landscaping. (Ord. 19-20 § 1 (Att.), 2020).

19.29.080 General provisions.

(1) Compliance. The landscaping standards are minimums; higher standards can be substituted as authorized by permit review criteria so long as fencing and vegetation do not exceed applicable height limits. The planning director may also increase, reduce or otherwise modify landscaping standards to the extent reasonably necessary for public safety, including traffic safety and crime prevention. In circumstances where the planning director reduces landscaping requirements due to public safety, the planning director may require enhanced landscaping in other parts of the project site to mitigate for the lost landscaping.

(2) Flexibility. This chapter does not intend to stifle creative problem solving but is rather a guideline for landscape requirements. Where strict interpretation of requirements is impractical, variances or administrative variances, as applicable, may be approved by the designated official as authorized by Chapter 19.40 BMC and BMC Title 20. Variances are not required where the planning director is given direct authority to waive a landscaping standard, such as in BMC 19.29.100(8).

(3) Minimum Landscaped Areas. For all projects to which this landscaping code is applicable, in no case shall the total amount of landscaping be less than 10 percent of the total site area.

(4) Protection of Street Trees. It shall be unlawful for any person without prior written approval of the city to remove, destroy, cut, break, or injure any street tree that is planted or growing in or upon any right-of-way.

(5) Retention of Existing Landscaping and Existing Trees Encouraged. Where possible, existing native trees and shrubs, rock outcroppings, and mature ornamental landscaping shall be preserved and incorporated in the landscape layout and can be counted towards required landscaping. Development or redevelopment of properties shall retain existing trees when possible and minimize the impact of tree loss during development. Landscape plans are subject to requirements specified in this chapter to protect significant trees and vegetation with habitat value.

(6) Calculation of Required Plantings. Some required landscaping areas require a minimum amount of plantings per square feet of area. If the calculation of the number of plantings results in a fraction of one-half or greater, the applicant shall round up to the next whole number. If the calculation of the number of plantings results in a fraction of less than one-half, the applicant shall round down to the next whole number.

(7) Avoidance of Hazards. All landscaping shall be planned in consideration of public health, safety, and welfare.

(a) Landscaping shall not intrude within the clear vision areas at driveways and street intersections;

(b) Trees planted near overhead power lines shall be species that will comply with utility purveyor clearance requirements;

(d) Crime prevention and safety should be considered in landscape design;

(e) Landscaping in a parking lot shall not conflict with the safety of those using a parking lot, abutting sidewalks, or with traffic safety.

(8) Vegetation Preference. Vegetation within required setbacks or screening areas shall be retained or planted in this order of preference: (a) native coniferous trees; (b) native deciduous trees; (c) other native vegetation. Vegetated low impact development stormwater facilities may be incorporated as part of landscaped setbacks or screening requirement.

(9) Plant Compatibility. All new plantings must be of a type which will thrive amid existing vegetation without killing or overtaking it. Incompatible plants which require different planting environments or microclimates shall not be mixed. Haphazard mixture of textures, colors and plant types should be avoided. Invasive, nuisance plants on the noxious weed list (state and Pierce County) are prohibited.

(10) Irrigation. Planting areas with nursery stock or transplanted vegetation shall include an automatic mechanical irrigation system designed for full coverage of the planting area.

Exceptions may be granted for native planting plans that provide temporary irrigation for at least three growing seasons.

(11) Preservation of Significant Views. Applicants are encouraged to consider and preserve views and vistas from public rights-of-way when determining placement of vegetation. While it is not the intent to avoid all trees in the foreground of a view, consideration should be given to the expected height of tree and how they might be located to “frame” the view. Notwithstanding any other provision of this chapter, trees and shrubs planted pursuant to the provisions of this chapter should be types and ultimate sizes at maturity that will not impair scenic vistas. (Ord. 19-20 § 1 (Att.), 2020).

19.29.090 Area and situation-specific landscaping requirements.

(1) Right-of-Way Strips. Between the property line and the edge of the curb or street paving, street trees, in compliance with BMC 19.29.100, shall be planted along arterial and collector streets. These street tree requirements pertain to new commercial and manufacturing buildings or change of occupancy, as defined by the International Building Code, within the following zones: CC, GC, HC, HDR, LI, and NMU; to new multifamily structures containing more than two units; and to improvements of at least 50 percent of the assessed property value. Street trees for residential subdivisions shall be required and installed in accordance with Buckley’s adopted Development Guidelines and Public Works Standards.

(2) Perimeter Landscaping Buffers.

(a) Perimeter landscaping buffers are defined in BMC 19.29.100, and include:

(i) Barrier buffers: required along the common side and rear property lines of properties where the proposed use is abutting an incongruous zone.

(ii) Visual relief buffers: required along the common side and rear property lines of properties where visual relief buffers are required.

(b) Perimeter buffer requirements are based on the congruity of zones and uses. Congruous zones include:

(i) Light industrial (LI) adjacent to other LI zones.

(ii) General commercial (GC) and central commercial (CC) adjacent to each other.

(iii) High density residential (HDR), R-6000, R-8000 or R-20,000 adjacent to each other.

Table 1: Guide for Applying Perimeter Buffer Requirements
	Adjacent property is zoned LI	Adjacent property is zoned GC or CC	Adjacent property is zoned NMU, HC, or P	Adjacent property is zoned HDR, R-6,000, R-8,000, or R-20,000
Proposed use in an LI zone	No buffer	Barrier buffer or no buffer1	Barrier buffer or no buffer1	Barrier buffer2
Proposed use in an GC or CC zone	Barrier buffer or no buffer1	No buffer	Barrier buffer or no buffer1	Barrier buffer2
Proposed use in an NMU, HC, P zone	Barrier buffer or no buffer1	Barrier buffer or no buffer1	Barrier buffer or no buffer1	Barrier buffer or no buffer1
Proposed use in HDR, R-6,000, R-8,000, or R-20,000 zone	Barrier buffer	Barrier buffer2	Barrier buffer2	No buffer

1 Depends on use congruity. See definition of “congruous.”

2 Except when proposed use is permitted outright in both zones.

Table 1 Exceptions:

1. When an existing nonconforming use is located on a parcel adjacent to a proposed use, and when that nonconforming use is incongruous with the proposed use, a barrier buffer shall be required along the common property line of the nonconforming use. A visual relief buffer may be considered as an alternative, if approved by the planning director, when the nonconforming use is not a residential use.

2. Visual relief buffers may be an acceptable alternative to barrier buffers, if approved by the planning director, when an adjacent incongruous use is not permitted outright but may be permitted as a conditional use.

3. When the proposed use is a residential use, perimeter buffers are not required.

4. Ten-foot visual relief buffers are required along the lot frontages for all new commercial and manufacturing buildings and uses within the CC, GC, HDR, LI, and NMU zones; for new multifamily structures containing more than two units, and to commercial, manufacturing or multifamily residential improvements of at least 50 percent of the assessed property value. This buffer shall be planted with trees of which 70 percent may be deciduous. One tree shall be provided for each 30 linear feet of landscaped area. The trees may be spaced irregularly or clustered. If the project is also subject to street tree requirements, then this requirement for frontage visual relief buffer trees may be waived.

(3) Building Facades. Facade buffers, as defined in BMC 19.29.100, shall be required for new commercial and manufacturing buildings or uses within the CC, GC, HC, HDR, LI and NMU zones; to new multifamily buildings containing more than two units; and to existing commercial, manufacturing or multifamily residential improvements of at least 50 percent of the assessed property value.

(4) Parking Lots. Vehicle parking lots shall meet minimum landscape standards in this section.

(a) Perimeter Landscaping. All parking lots shall meet parking lot perimeter buffer requirements as described in BMC 19.29.100.

(b) Minimum Amounts of Interior Parking Lot Landscaping. Surface parking lots with 15 or more stalls shall be landscaped with at least 20 square feet per parking space of parking lot canopy buffer plantings and trees as identified in BMC 19.29.100.

(c) Shading. Parking lots shall be designed to provide a minimum of 50 percent canopy shading within 10 years of planting. All required landscaping area widths shall be measured from back of curb to back of curb.

(d) Perimeter Versus Interior Landscaping. Perimeter landscaping may not substitute for interior landscaping.

(e) Optional Layouts. The following graphics are optional yet recommended layouts for meeting interior and perimeter landscaping requirements:

Parking Lot Landscaping Examples:

(Ord. 19-20 § 1 (Att.), 2020).

19.29.100 Description of required landscaping types.

The following are descriptions of individual landscaping types and buffers described in BMC 19.29.090:

(1) Street Trees. Such landscaping shall include a mixture of trees, shrubs, and ground cover as approved by the planning department.

(a) Street trees shall be planted by the land owner or developer according to city public works standards.

(b) Where tree branches might interfere with pedestrians or vehicles in the right-of-way, trees should have a clear trunk area of seven feet above the ground for pedestrian paths, eight feet above bicycle lanes, 15 feet above arterial streets, and 14 feet above all other streets.

(c) Spacing of street trees shall be a minimum of 40 feet apart on arterial streets and up to 30 feet on collector and local streets.

(d) In the historic commercial zone, a combination of potted street trees, lamp posts, planter boxes, hanging baskets or other landscaping or street furniture may be substituted for street trees upon approval by the decision maker as recommended by the planning director and/or city engineer.

(e) Property owners on local access streets are encouraged to plant street trees in accordance with public works standards and recommended species type as adopted by resolution.

(f) Property owners are encouraged to plant or retain vegetation other than trees within the right-of-way strip between the property line and the edge of the curb or street paving. This shall include vegetation used within low impact development facilities and shall not obscure visibility.

(2) Barrier Buffer. These buffers should create a sight-obscuring barrier, as follows:

(a) Use either 20 feet of landscaping, or 10 feet of landscaping plus fencing, that shall be, at minimum, six feet high at planting and 100 percent sight-obscuring within three years.

(b) Specifically when the barrier buffer is required adjacent to a residential zone, a permanent, fully sight-obscuring fence shall be required.

(c) Evergreen shrubs and ground cover to provide 75 percent coverage of landscaping area within two years after planting.

(3) Visual Relief Buffer. Such landscaping or landscape plus fencing shall be, at minimum, six feet high at time of planting. Partially sight-obscuring buffers provide a transparent buffer to soften the appearance of parking lots. The buffer shall be constructed around the site perimeter as follows:

(a) Eighty-five percent of trees may be deciduous. One tree shall be provided for each 30 linear feet of landscaped area. The trees may be spaced irregularly or clustered.

(b) Evergreen shrubs and ground cover to provide 75 percent coverage of landscaped area within two years after planting.

(c) Vegetation used within low impact development facilities shall be considered as part of these landscaping requirements as approved by the public works director.

(d) Buffer shall be at least 50 percent sight-obscuring.

(4) Facade Buffer. Blank walls shall include a narrow planting area, where feasible, with shrubs or vines (espaliers) giving coverage to the wall.

Facade buffers should accent the character of the building. Street trees, window boxes, planters and hanging pots within the public right-of-way are acceptable, subject to approval by the planning director or city engineer. These items should not create a hazard by inhibiting pedestrian movement in the right-of-way and shall comply with required sight distances at intersections. The planting material should soften the transition between the pavement and the building. Blank building walls should be softened by landscaping. Plantings may be arranged formally or informally. Vegetation used within low impact development facilities shall be considered as part of these landscaping requirements as approved by the public works director.

Within the historical commercial zone, potted street trees, planter boxes and street furniture within the public right-of-way may be substituted for the above facade landscaping upon approval by the decision maker and recommended for approval by the city planning director or city engineer.

(5) Parking Lot Canopy Buffer. Parking lots shall be designed to provide a minimum of 50 percent canopy shading within 10 years of planting. Any interior parking lot landscaping area shall be sized to dimensions of at least eight feet by 12 feet. Landscaping shall be dispersed throughout the parking area and shall include a mixture of trees, shrubs, and ground cover as follows:

(a) Trees shall be two inches in DBH for multifamily, commercial, and industrial uses. At least one tree for every six parking spaces within the lot interior shall be planted. At least 30 percent of the required trees shall be evergreen.

(b) Shrubs at the minimum rate of one per 20 square feet of landscaped area shall be planted. Up to 50 percent of shrubs may be deciduous.

(c) Ground cover shall be planted in sufficient quantities to provide at least 75 percent coverage of the landscaped area within three years of installation.

(d) There shall be no more than 50 feet between parking stalls and an interior parking lot landscape area.

(e) Landscaped islands the same dimensions and alignment as the parking spaces shall be installed at the ends of each row of parking spaces and separating every 12 spaces within rows of parking spaces. Each landscaped island shall have at least one tree, and at least 15 percent of the trees shall be evergreens. The number of required parking spaces may be reduced by one space for each landscaped island provided.

(f) Planting strips and landscaped islands within parking lots shall be protected from vehicular access by a curb or landscaping timber border.

(6) Parking Lot Perimeter Buffer. Such landscaping shall be at least 10 feet in width as measured from the street right-of-way. Standards for planting shall be as follows:

(a) Trees shall be two-inch caliper for multifamily, commercial, and industrial uses at an average minimum rate of one tree per 30 lineal feet of street frontage. Trees shall be one-and-one-half-inch caliper for low impact development stormwater management facilities associated with any land use.

(b) Shrubs at the minimum rate of one per 20 square feet of landscaped area. Up to 50 percent of shrubs may be deciduous.

(c) Ground cover in sufficient quantities to provide at least 75 percent coverage of the landscaped area within three years of installation.

(7) Riparian Zone Buffer. This design pertains to all parcels and sites within the city of Buckley. Unless replaced as part of development mitigation, original vegetation along streams, wetlands, water sources and drainage channels must be maintained in order to continue natural erosion control and ground water recharge. Permits and procedures established in the city wetlands and critical areas ordinance must be followed in these areas.

(8) Buffer Alteration. The planning director has the ability to allow modifications or deviations from landscaping buffer standards, without the need for a variance, when all of the following conditions exist:

(a) Another engineering solution is possible.

(b) There is little visual impact to external properties.

(c) The applicant can demonstrate the end product will result in a higher quality or a demonstrably more desirable outcome. (Ord. 19-20 § 1 (Att.), 2020).

19.29.110 Protection of significant trees and existing native vegetation.

(1) Areas of native vegetation which are designated as landscape or buffer areas, or which are otherwise retained under the provisions of the Buckley design guidelines, shall be subject to a 10-foot setback from any native tree larger than six inches DBH. Clearing, grading or contour alteration is not permitted within this no-construction area unless a qualified arborist provides written documentation that proposed construction activity within the 10-foot setback will not harm existing vegetation within the designated landscape or buffer area.

(2) Encroachment into Drip Line. No construction activities shall take place within the drip line of a tree to be retained without extra precautions as recommended by a qualified arborist. The applicant may install impermeable or compactible surface within the area defined by the drip line if it is demonstrated by a qualified arborist that such activities will not endanger the tree or trees.

(3) Grading. If the grade level adjoining a tree to be retained is to be altered to a degree that would endanger the viability of a tree or trees, then the applicant shall construct a dry rock wall or rock well around the tree. The diameter of this wall or well must be capable of protecting the tree beyond a no-construction zone or as approved by a qualified arborist.

(4) Tree Protection Barricade. All significant trees to be retained must be protected during construction by installation of a protective barricade. This will require preliminary identification of the proposed area of disturbance for staff inspection and approval, then installation of a protective barricade before major excavation with heavy equipment begins. The barricade must be made of cylindrical steel posts or four-inch by four-inch wood posts with chain link fence attached. Fence posts shall be eight feet on center connected with two-inch by four-inch top rails or equivalent support system. Fence height must be a minimum of four feet high.

(5) All significant trees within required landscaped buffers shall be preserved, including within barrier buffers, visual relief buffers, and parking lot canopy buffers. Any significant trees retained within required landscaped buffers shall count toward fulfillment of said buffer requirements.

(6) For an entire lot, a minimum of 30 percent of significant trees shall be preserved, which includes those preserved in landscaping buffers.

(7) Any significant trees that are removed within the 30 percent minimum requirement for significant tree retention shall be replaced in a 2:1 ratio with new native trees, with each replacement tree a minimum of two inches DBH.

(8) For any tree that may be considered a danger tree by the developer, the applicant shall obtain approval from the planning director prior to removal. (Ord. 02-22 § 10, 2022; Ord. 19-20 § 1 (Att.), 2020).

19.29.120 Installation standards.

(1) Soil Preparation. Before any plant material is installed, all soil shall be prepared to be conducive to the healthy growth of the new plants. The fill is to be rich in organic material; clay soils are not acceptable. All construction materials (concrete residue, rocks, etc.) shall be removed from the landscaping area prior to landscaping. The new topsoil should provide an adequate transition from new topsoil to original native soil and include compost to assist in proper soil composition.

(2) Irrigation. Automated or manual irrigation must be supplied as needed for the first two years to guarantee the survival of the new plants. Irrigation-free landscape schemes and drought-resistant trees and ground cover are encouraged.

(3) Installation. All plans shall indicate the method of planting and tree staking. For trees, soil preparation shall be at least 12 inches deep, or as deep as the root ball, and planting pits shall be three times the diameter of the root ball to be planted. When trees are staked, the staking procedure should not damage the bark, limbs or ball. All stakes and attachments shall be removed by the landscape contractor or property owner by the end of the second growing season. Root barriers shall be provided for all trees and shrubs planted adjacent to planting strips, islands, streets and/or sidewalks.

(4) Minimum Plant Sizes at Installation.

(a) One-and-one-half-inch minimum caliper for street trees and other deciduous trees.

(b) Six-foot minimum height for evergreen trees.

(d) Eighteen-inch minimum height for medium and tall shrubs.

(5) Maximum Spacing for Shrubs and Ornamental Grasses.

(a) Small shrubs: three feet on center.

(b) Medium shrubs: four feet on center.

(6) Ground Cover. All planting bed areas shall provide 75 percent coverage within two years and 50 percent at the time of planting. Spacing is as follows:

(a) One-gallon containers, 18 inches on-center (o.c.).

(b) Four-inch pots, 15 inches o.c.

(d) Grass sod areas to be 100 percent coverage.

(7) Mulching. All planting areas shall be mulched with a uniform two-inch layer of shredded bark mulch. Trees are not to be ringed with mulch. Mulch does not satisfy the requirement for ground cover; it is only used as a weed deterrent. Over-mulching, more than four inches deep, may cause plant health problems.

(8) Quality. Plant materials used shall be equivalent to available nursery-grown stock. All plants shall be compatible with the character and climate of the Pacific Northwest. In some cases exotics may be the preferred plant type depending on wind and moisture exposure. Street trees shall be of a variety suitable for the growing space above and below the ground, with special consideration given to utilities, sidewalks and proximity to the street and buildings.

(9) Grading. Graded slopes in landscaped areas should not exceed a two to one (2:1) slope. All graded landscaping areas should be planted as soon as possible after the disturbance. If landscaped areas are bonded and to be planted at a later date, graded areas shall be temporarily stabilized with erosion control devices.

(10) Sight Obstructions. No landscaping shall impair vision at a corner lot or driveway entrance/exit. (See BMC 19.22.040.) In these areas, all landscaping shall be planted and maintained at a height no greater than two and one-half feet above street grade. Tree trunks must be kept clear of branches below 10 feet above street grade.

(a) Corner Lot. A sight distance triangle shall be created when two or more public rights-of-way intersect. Two sides of the triangle should extend no less than 30 feet from the intersection point. The hypotenuse of the triangle is the connection points opposite the intersection point.

(b) Driveways. Private driveways entering a city street shall have a triangular sight area 10 feet perpendicular to the street right-of-way and 30 feet along the street right-of-way on each side of the driveway. (Ord. 19-20 § 1 (Att.), 2020).

19.29.130 Maintenance requirements.

(1) Whenever landscaping is required under the provisions of this chapter, shrubs and trees in the landscaping and planting areas shall be maintained in a healthy growing condition. Planting beds shall not be located over impermeable surfaces. Dead or dying trees or shrubs shall be replaced immediately, and the planting area shall be maintained reasonably free of noxious weeds and trash.

(2) Similarly, if necessary, the trees or shrubs shall receive pruning or removal to avoid the creation of a safety hazard or nuisance through excessive shading, overhanging adjacent properties or to preserve a view.

(3) Areas of natural vegetation shall be retained over time to maintain the health and fullness of natural vegetation and buffer areas. (Ord. 19-20 § 1 (Att.), 2020).