ARTICLE I. LANDSCAPING AND TREE PROTECTION PROVISIONS
SECTION:
8-4I-3: General Landscaping Standards And Irrigation Provisions
8-4I-4: Landscaping Provisions For Specific Uses
8-4I-5: Perimeter Landscaping Provisions
8-4I-6: Parking Lot Landscaping Provisions
8-4I-7: Tree Preservation Provisions
8-4I-9: Landscape Maintenance Provisions
8-4I-1: PURPOSE:
A. To implement the goals and objectives of the comprehensive plan to "emphasize the garden in Garden City" and more specifically:
1. Improve the landscaping standards for all new development.
2. Beautify sidewalks and gateways with landscaping and trees.
3. Continue to require sidewalks and landscaping in all new development, and in major alterations and reuse of existing commercial sites.
4. Identify appropriate native plants and landscaping techniques for landscaping along the river. Require that new developments have landscaping consistent with those guidelines.
B. To enhance the livability, aesthetic qualities, economic attractiveness, and environmental health of the city.
C. To achieve a balance between the right of individuals to develop and maintain their property in a manner they prefer and the rights of city residents to live, work, shop, and recreate in pleasant, healthy, and attractive surroundings.
D. To promote the use of native and other low water use plant materials, and to discourage landscaping that requires high water use for maintenance, such as large expanses of lawn.
E. To require best practices in the maintenance of landscaping and the preservation of existing significant vegetation and trees. (Ord. 898-08, 9-8-2008)
8-4I-2: APPLICABILITY:
All development, redevelopment, additions, or site modifications to existing development shall be required to conform to this article based upon the following guidelines:
A. Additions less than twenty five percent (25%) of the gross floor area of the existing structure or developed area, no additional landscaping shall be required.
B. Except for residential uses, additions or site modifications that are twenty five percent (25%) to fifty percent (50%) of the gross floor area of the existing structure or developed area, streetscape landscaping as required by section 8-4I-8 of this article shall be installed.
C. Except for single-family and two-family residential uses, additions or site modifications greater than fifty percent (50%) of the gross floor area of the existing structure or developed area, shall comply with all provisions of this article.
D. Restriping, parking lot overlays with no increase in the square footage of the parking area, or parking lot replacement less than twenty five percent (25%), no additional landscaping as required by section 8-4I-6, "Parking Lot Landscaping Provisions", of this article shall be required.
E. Parking lot replacement that is twenty five (25) to fifty percent (50%) of the parking area, shall comply with the requirements of section 8-4I-5, "Perimeter Landscaping Provisions", of this article.
F. Parking lot replacement that is greater than fifty percent (50%) of the parking area shall comply with all requirements of sections 8-4I-5, "Perimeter Landscaping Provisions", and 8-4I-6, "Parking Lot Landscaping Provisions", of this article.
G. For all new residential and nonresidential uses, all landscaping standards of this article shall be met. (Ord. 898-08, 9-8-2008)
8-4I-3: GENERAL LANDSCAPING STANDARDS AND IRRIGATION PROVISIONS:
A. Landscape improvements shall be an integral part of the overall site design for each property.
1. Landscape areas shall be configured to maximize their interconnectivity within the site and to landscape or natural areas in adjacent developments. Except in parking lots and for screening along roadways, small, isolated islands of landscaping shall be avoided;
2. Landscape areas shall be compatible with the character of the proposed development and the surrounding areas to reinforce neighborhood identity;
3. Landscape design shall enhance natural drainageways and environmental features;
4. Spacing of trees and shrubs shall allow for their natural spread; and
5. A three foot (3') clearance zone shall be maintained around the circumference of fire hydrants.
B. Retain and protect existing trees, vegetation, and native soils and integrate these features into the overall landscape plan.
C. Landscape improvements shall follow water efficient design principles to facilitate water conservation as set forth in the "Garden City Design And Construction Guide", as amended.
D. All landscaping shall conform to the standards for approved and prohibited plant materials and tree species as set forth in the "Garden City Design And Construction Guide".
E. The following minimum plant sizes shall be used for all required landscape areas:
|
Shade trees |
2 inch caliper minimum |
|
Ornamental trees |
2 inch caliper minimum |
|
Evergreen trees |
6 foot height minimum |
|
Woody shrubs |
2 gallon pot minimum |
F. Required landscape areas shall be at least seventy percent (70%) covered with vegetation at maturity, with mulch used under and around the plants. Use of mulch, organic or rock, as the only ground cover in required planting areas is prohibited.
G. When five (5) or more trees are to be planted to meet the requirements of any portion of this article (including street trees, perimeter landscaping, parking lot landscaping and other landscape guidelines) a mix of species shall be provided. The number of species to be planted shall vary according to the overall number of trees required as set forth in table 8-4I-1 of this subsection. (Ord. 898-08, 9-8-2008)
|
Required Number Of Class II Or Class III Trees |
Minimum Number Of Species |
|---|---|
|
5 to 10 |
2 |
|
11 to 30 |
3 |
|
31 to 50 |
4 |
|
More than 50 |
5 |
(Ord. 944-12, 5-14-2012)
H. All plant material installed pursuant to this article shall meet or exceed the minimum federal standards as regulated by ANSI Z60.1, American standard for nursery stock.
I. All trees, shrubs, and other plant material shall be planted using accepted nursery standards as published by the American Association Of Nurserymen (latest edition) including hole size, backfilling, and fertilization.
J. Tree staking is not required, but may be used in areas with high winds or other situations that make staking desirable. If trees are staked, the stakes shall be removed within twelve (12) months to prevent damage to the tree.
K. All planting areas that border driveways, parking lots, and other vehicle use areas shall be protected by curbing, wheel stops, or other approved protective devices.
1. Trees shall be planted at least three feet (3') from curbs, sidewalks, driveways and other hard surfaces to buffer from stress caused by vehicle overhang and compacted soils, or planted with sufficient space to provide for the full maturity of the particular tree species.
2. All other plant material, except sod or ground cover, shall be set back a minimum of one foot (1') from any curb edge to protect from vehicle overhang and mechanical damage.
L. The landscape installation shall stabilize all soil and slopes.
M. Berm slopes are generally discouraged, but shall not exceed two to one (2:1) (horizontal to vertical). Three to one (3:1) maximum slopes are recommended. Grass that requires mowing shall not be used on slopes steeper than three to one (3:1).
N. All required landscaping shall be provided with an automatically controlled irrigation system in conformance with the best management practices for automatic irrigation systems set forth in the "Garden City Design And Construction Guide". (Ord. 898-08, 9-8-2008)
O. Required trees must be identified in the most current version of "Tree Selection Guide For Street And Landscapes Throughout Idaho" by Boise parks and recreation department or certified by a licensed landscape architect to be appropriate to the proposed location. (Ord. 944-12, 5-14-2012)
8-4I-4: LANDSCAPING PROVISIONS FOR SPECIFIC USES:
A. Landscaping For Single-Family Residential Units:
1. For lots with thirty (30) to forty nine feet (49') of linear frontage, one class II or class III tree shall be planted in the front yard setback.
2. For lots with fifty feet (50') or more of linear frontage, two (2) class II or class III trees shall be planted with one tree located in the front yard setback. (Ord. 944-12, 5-14-2012)
3. Trees shall be planted with adequate spacing to allow for the mature spread of the trees.
B. Landscaping For Townhouse, Two-Family Duplex, And Multi-Family Dwelling Units; Manufactured And Mobile Homes And All Nonresidential Uses:
1. A minimum of five percent (5%) of the gross site area shall be landscaped areas, excluding areas for setback or perimeter landscaping. (Ord. 898-08, 9-8-2008)
2. A minimum of one class III or class II tree shall be planted in the frontage and every adjacent streetside. An additional class I tree shall be planted in the corresponding setback for every increment of fifty feet (50') of linear feet of frontage. (Ord. 944-12, 5-14-2012)
3. A minimum of one tree per one thousand (1,000) square feet of landscaped area and one shrub per one hundred fifty (150) square feet of landscaped area shall be planted.
a. Trees shall be selected from the city’s approved list of appropriate tree species contained in the "Garden City Design And Construction Guide".
b. Trees shall be distributed throughout the site.
c. Shrubs shall be grouped and distributed throughout the site.
4. Trees may be substituted for up to one-half (1/2) of the required shrubs at the rate of one tree for ten (10) shrubs and vice versa. (Ord. 898-08, 9-8-2008; amd. Ord. 944-12, 5-14-2012)
5. Class II or class III trees can be substituted at the rate of two (2) class I trees for every one class II or class III trees unless otherwise specified by an adopted street design or master plan. (Ord. 944-12, 5-14-2012)
8-4I-5: PERIMETER LANDSCAPING PROVISIONS:
A. Purpose: The perimeter landscaping shall provide the following benefits:
1. To provide a visual barrier between different land uses;
2. To enhance the streetscape;
3. To provide privacy; and
4. To protect uses from wind, dust, noise, traffic, glare, visual disorder, and harmful or noxious effects. (Ord. 898-08, 9-8-2008)
B. Applicability: Required perimeter landscaping meeting the standards set forth in subsection C of this section is required in the following situations:
1. Between a new or substantially altered nonresidential use and a residential use or vacant residentially zoned property where such uses are not separated by an arterial street; (Ord. 944-12, 5-14-2012)
2. Along the common property line between an adjacent nonresidential use and a residential use or vacant residentially zoned property;
3. Along the common property line between a multi-family residential use and a single-family or two-family residential use or vacant single-family or two-family zoned property;
4. Between a nonresidential or multi-family use and a public park;
5. Between a loading or utility service area, vehicle repair bay, or vehicle fueling area and all property lines;
6. Between other paved vehicular use areas, including driveways, and vehicle storage areas and all property lines;
7. Between a carport for five (5) or more vehicles serving a residential use and an adjoining lot with a residential use or vacant residentially zoned property.
C. Standards:
1. A perimeter landscaping area shall be at least ten feet (10') wide measured from the property line to the interior of the lot;
2. A screen consisting of vegetation shall be at least six feet (6') wide and six feet (6') in height at maturity;
3. At least one tree shall be planted for every fifteen (15) linear feet of perimeter length (or as appropriate to the selected species) to quickly establish continuous canopy coverage.
4. Additional standards for parking lots and carports are set forth in section 8-4I-6, "Parking Lot Landscaping Provisions", of this article.
5. Structures less than one hundred twenty (120) square feet, including, but not limited to, trash enclosures and storage sheds may encroach into the perimeter landscape area.
6. Perimeter landscape areas shall provide for pedestrian access from residential development to abutting commercial districts and vice versa. (Ord. 898-08, 9-8-2008)
8-4I-6: PARKING LOT LANDSCAPING PROVISIONS:
A. Purpose: Landscape areas shall be distributed throughout a parking lot to soften and screen parking lot edges, reinforce circulation routes, create pleasant pedestrian conditions and maximize shade and stormwater benefits. (Ord. 898-08, 9-8-2008)
B. Applicability: The provisions of this section shall apply to all new or substantially altered parking lots of five (5) spaces or more. (Ord. 944-12, 5-14-2012)
C. Standards:
1. Landscaped areas in large parking lots shall be consolidated to enhance tree and plant material growing conditions.
2. Landscaped areas shall be designed to accommodate the following:
a. Trees shall be planted with access to at least five (5) square feet of area and three (3) in depth of quality soil prepared to the specifications set forth in "Garden City Design And Construction Guide".
b. High branching, deciduous shade trees planted evenly at fifteen foot (15') intervals (or as appropriate to the selected species) to quickly establish continuous canopy coverage.
3. Plant materials for parking lot landscape areas shall be selected for suitability in that environment:
a. Native and nonnative plant species that are hardy, drought tolerant, and resistant to the stresses of compacted soils and weather exposure shall be used;
b. Suitable native species shall be included where possible and appropriate;
c. Invasive species shall not be planted near the Boise River greenbelt and other natural areas;
d. Monocultures which can be susceptible to disease shall be avoided;
e. Consideration to the sun, shade and irrigation requirements shall be made; and
f. A variety of deciduous and coniferous trees and shrubs for year round interest, texture, shape and seasonal color shall be planted.
4. Landscape areas shall be coordinated with the location of light standards and other utilities.
D. Perimeter Landscaping And Screening Standards:
1. Edge treatments along streets and other public spaces shall visually screen parked vehicles, but not completely obstruct views into and out of the parking lot for the purpose of supporting pedestrian safety and security.
2. Solid masonry or wood fencing a minimum of six feet (6') in height with landscaped screening shall be provided between parking lots and residential uses or vacant residentially zoned properties.
Figure 8-4I-2
Examples Of Landscaping And Walls To Screen Parking Lots
E. Internal Landscaping Standards:
1. Landscaped areas, including islands, medians, and stormwater retention areas shall be designed within the parking lot to define major vehicle and pedestrian routes, provide shade and break up the expanse of paved areas.
2. Internal landscaped areas shall be designed with a curb to prevent damage from vehicles, to separate planting areas from pedestrian pathways, and to prevent soil and other landscape material from spreading over adjacent surfaces.
a. Taller or shorter curbs are permitted where vehicle overhang and door clearances are not an issue.
b. Curb cuts are permitted to the extent needed to support accessibility and stormwater initiatives.
3. Plant high branching deciduous trees throughout the parking lot interior to provide shade for pedestrians, vehicles and surfaces.
a. Internal shade trees shall be provided at a minimum ratio of one tree planted for every five (5) parking spaces supplied.
b. Internal shade trees shall be planted such that no parking space is more than one hundred feet (100') from a tree.
c. On small or narrow sites, shade trees provided in non-street facing perimeter planting areas can be counted toward the internal tree requirement, provided that the maximum distance from a parking space one hundred feet (100'), is met.
4. Include landscaped islands with at least one tree at the beginning and end of each parking row and to break up longer rows or highlight special features.
5. A continuous landscape median at least ten feet (10') in width shall be provided every three (3) banks of parking (a bank is 2 rows of parking and a drive aisle).
Figure 8-4I-3
Examples Of Internal Parking Lot Landscaping
(Ord. 898-08, 9-8-2008)
8-4I-7: TREE PRESERVATION PROVISIONS:
A. Purpose: The provisions of this section are intended to preserve existing trees of four inch (4") caliper or greater from destruction before and during the development process.
B. Applicability: Tree preservation is required in all districts.
C. Standards:
1. Site development shall make all feasible attempts to maintain existing trees four inch (4") caliper or greater within their design.
2. Existing trees that are retained shall be protected from damage to bark, branches, and roots during construction in accordance with the provisions set forth in the "Garden City Design And Construction Guide".
3. Any tree damaged during construction shall be replaced in accordance with subsection C5 of this section.
4. Construction, excavation, or fill occurring within the drip line of any existing tree shall be avoided. Specific requirements for construction within the drip line of existing trees are as follows:
a. Impervious paving surfaces shall remain outside of the drip line of existing trees.
b. Grade changes greater than six inches (6") are prohibited within the drip line of existing trees.
c. A fence or barrier that encloses the entire area beneath the tree canopy shall be in place prior to construction. (Ord. 898-08, 9-8-2008)
d. New underground utilities to be placed within the drip line of existing trees shall be installed in accord with subsection D of this section. (Ord. 905-09, 3-23-2009)
5. Mitigation shall be required for all existing trees four inch (4") caliper or greater that are removed or damaged from the site.
a. Mitigation is required for all such trees removed within eighteen (18) months prior to issuance of the building permit for construction on the site or damaged during construction.
b. Mitigation shall be replacement of the total calipers lost on site up to an amount of one hundred percent (100%) replacement. (Example: Two 10-inch caliper trees removed may be mitigated with four 5-inch caliper trees, five 4-inch caliper trees, or seven 3-inch caliper trees.)
c. Mitigation trees are in addition to all other landscaping required by this article.
d. No mitigation is required in the following: 1) existing prohibited trees as specified in the "Garden City Design And Construction Guide" within the street buffer or parking lot; 2) existing dead, dying, or hazard trees certified prior to removal by a certified arborist; 3) trees that are required to be removed by another governmental agency having jurisdiction over the project.
6. Existing trees that are retained or relocated on a site may count toward the required landscaping.
D. Standards For Planting Of Trees Near Existing Utilities And To Trenching For New Utilities Near Existing Trees:
1. Overhead Utilities: Only class I trees as set forth in the "Garden City Design And Construction Guide" recommended plant list may be planted under or within ten (10) lateral feet of any overhead utility wires.
2. Underground Utilities: All trees shall be planted outside of any easement that contains a city water or sewer main, unless written approval is obtained from the city engineer. If any utility easement precludes trees required by this article, the width of the required buffer shall be increased to accommodate the required trees.
3. Trenching: New underground utilities shall stay outside of the drip line of existing trees if trenched, or be tunneled a minimum of three feet (3') below existing grade within the tree’s drip line.
a. No root two inches (2") or larger shall be cut.
b. This requirement is for placement of new utilities and does not affect the city’s ability to access existing utilities for repair and maintenance. (Ord. 898-08, 9-8-2008)
8-4I-8: RESERVED:
(Ord. 898-08, 9-8-2008)
8-4I-9: LANDSCAPE MAINTENANCE PROVISIONS:
A. Purpose: The provisions of this section are intended to ensure that all required landscaping is maintained in a healthy, growing condition at all times.
B. Applicability: The requirement for landscape maintenance applies in all districts where landscaping has been required.
C. Standards:
1. The property owner is responsible for the maintenance of all landscaping and screening devices required by this article.
2. Topping any street tree required by this article is prohibited.
3. Tree grates shall be widened to accommodate the growing tree trunk and prevent girdling of any trees planted in tree wells within sidewalks or other public right of way.
4. Plant materials which exhibit evidence of insect pests, disease, and/or damage shall be appropriately treated to correct the problem. Dead plant materials shall be replaced.
5. Where landscaping might impact motorist or pedestrian sight distance, shrubs shall be maintained below three feet (3') in height and trees shall be pruned so that the lowest branches will be at least seven feet (7') above the ground level.
6. All landscaping required by this subsection may be subject to periodic inspections by city officials to determine compliance or to investigate. (Ord. 898-08, 9-8-2008)