§ 153.536 MATERIALS.
   (A)   General. Landscaping may consist of a combination of groundcovers, shrubs, vines, trees, and garden areas. Landscape may also include incidental features such as stepping stones, benches, fountains, sculptures, decorative stones, or other ornamental features, placed within a landscaped setting.
      (1)   Plants having similar water use shall be grouped together.
      (2)   Except for garden areas, plant materials shall be selected from among those species and varieties known to thrive in the San Gabriel climate and where applicable, selected from an approved list maintained by the city.
      (3)   Installation of invasive plant species is prohibited as listed on the California Invasive Plant Council (Cal-IPC) list of Exotic Pest Plants of Greatest Ecological Concern in California.
      (4)   Site drainage shall be directed toward landscaped areas wherever feasible.
   (B)   Landscaped areas greater than 2,500 square feet. Where the total landscape area is equal to or greater than 2,500 square feet for commercial, industrial, and institutional projects or equal to or greater than 5,000 square feet for single-family and multi-family residential projects, the following landscape material limitations apply.
      (1)   Exclusive of garden areas, at least 60% of all plants and trees must be native or low water use.
      (2)   A maximum of 25% of the required landscape areas shall be turf or planted with other high water use plants except for turf areas that comprise an essential component of a project (e.g., golf courses or playing fields), which are exempt from this limit.
      (3)   The installation of turf on slopes greater than 25% is prohibited.
      (4)   No portion of turf areas shall be less than eight feet wide. Landscaped areas less than ten feet wide shall be irrigated with sub-surface drip or other technology that produces no over spray or runoff.
   (C)   Ground cover materials. Ground cover shall be of live plant material. Groundcover may include grasses. Pervious non-plant materials such as permeable paving, gravel, colored rock, cinder, bark, and similar materials shall not cover more than 15% of the area required to be landscaped, except with approval of a minor deviation to the landscape plan. Existing turf in residential zones may be replaced with synthetic grass or artificial turf, subject to said materials meeting design standards developed by the city. Mulch must be confined to areas underneath shrubs and trees and is not a substitute for ground cover plants.
   (D)   Mulch. A minimum two inch layer of mulch shall be applied on all exposed soil surfaces of planting areas except in turf areas, creeping or rooting ground covers or other special planting situations where mulch is not recommended. Stabilizing mulching products shall be used on slopes.
   (E)   Size and spacing. Plant materials shall be grouped in hydrozones in accordance with their respective water, cultural (soil, climate, sun and light) and maintenance needs. Plants shall be of the following size and spacing at the time of installation. The figures contained in this section are for illustrative purposes only and do not imply that the concept illustrated be implemented precisely as shown but rather in a manner consistent with the purpose of these regulations:
      (1)   Ground covers. Ground cover plants other than grasses may be planted from flats or from four-inch pots. Areas planted in ground cover plants other than grass seed or sod must be planted at a rate of one per 12 inches on center unless otherwise approved by the Director based on plant spread.
      (2)   Shrubs. When planted to serve as a hedge or screen, shrubs shall be planted at a minimum size of five gallons and have an expected mature height of six to eight feet and a mature spread of three to five feet. Shrubs planted to serve as a hedge shall be spaced three to five feet apart depending on the plant species.
   FIGURE 153.536-(E)(2): GROUND COVER AND SHRUB PLANTING
      (3)   Trees. Trees shall be provided as follows:
         (a)   One tree for every 1,000 square feet of net lot area for new commercial and residential development.
            1.   If the lot size or other site conditions make planting of the required trees impractical to comply with, the trees may be planted off-site in the public right-of-way or in public parks at twice the ratio with Director approval.
            2.   If the required number and size of trees already exist on the site, the applicant shall not be required to plant new trees on-site. Instead, the existing trees shall be shown on the site and landscape plans submitted to the Planning Division, and those trees shall be maintained in compliance with the standards of this section.
         (b)   At least one tree shall be located in the front yard of new residential development. If a tree does not already exist in the front yard, a tree shall be planted.
         (c)   A minimum of 15% of the trees planted shall be 24 inch-box or greater in size. All other trees shall be a minimum of 15 gallons in size with a one-inch diameter at breast height (dbh).
         (d)   A minimum of 50% of trees shall be an evergreen type.
         (e)   Newly planted trees shall be supported with stakes or guy wires.
         (f)   Any tree to be planted along a lot line or adjacent to a structure shall be no closer to said lot line or structure than one-half the diameter of the particular species’ drip line at maturity, measured from the center of the tree.
   FIGURE 153.536-(E)(3): TREE LAYOUT AND STAKING
 
(Ord. 601-C.S., passed 3-4-14; Am. Ord. 622-C.S., passed 11-17-15)