Landscape standards and specification.
§ 255-1740. Landscape standards and specification.
A. The following standards and specifications shall apply for minimum plant measurements, installation techniques and maintenance:
(1) The landscape contractor shall furnish and install and/or dig, ball, burlap, and transplant all plant materials listed on the plant schedule. Bare-root is typically not permitted for any tree.
(2) Plant materials shall conform to the requirements described in the latest edition of American Standard for Nursery Stock, published by the American Association of Nurserymen. Plants shall be nursery grown.
(3) Plants shall conform to the measurements specified in the plant schedule.
(a) Caliper measurements shall be taken six inches above grade for trees under four inches in diameter and 12 inches above grade for trees four inches in diameter and larger.
(b) Minimum branching height for all shade trees shall be six feet.
(c) Minimum size for shade trees shall be between 2 1/2 and three inches in diameter, and 12 feet to 14 feet in height.
(d) Minimum size for evergreen trees shall be between six feet to eight feet in height.
(e) Minimum size for shrubs shall be three feet in height.
(4) A professional horticulturist/nurseryman shall be consulted to determine the proper time to move and install plant material so that stress to the plant is minimized. Planting of deciduous material may be continued during winter months provided there is no frost in the ground and frost-free topsoil planting mixtures are used.
(5) A landscape contractor shall excavate all plant pits, vine pits, hedge trenches, and shrub beds as follows:
(a) All pits shall be generally circular in outline, with vertical sides. The tree pit shall be deep enough to allow 1/8 of the ball to be above the existing grade. Plants shall rest on undisturbed existing soil or well-compacted backfill. On every side, the tree pit must be a minimum of nine inches larger than the ball of the tree.
(b) If areas are designated as shrub beds or hedge trenches, they shall be cultivated to at least 18 inches in depth. Areas designated for ground covers and vines shall be cultivated to at least 12 inches in depth.
(6) Each tree, shrub, or vine shall be pruned in an appropriate manner, in accordance with accepted standard practice.
(7) All trenches and shrub beds shall be edged and cultivated to the lines shown on the drawing. The areas around isolated plants shall be edged and cultivated to the full diameter of the pit. Sod that has been removed and stacked shall be used to trim the edges of all excavated areas to the neat lines of the plant pit saucers, the edges of shrub areas, hedge trenches, and vine pockets.
(8) After cultivation, all plant materials shall be mulched with a layer between two inches and three inches deep of tan bark, peat moss, or another material over the entire area of the bed, or saucer.
(9) Earthen berms shall only be used in conjunction with vegetative planting.
B. Existing trees and woodlands shall be preserved to the greatest extent possible. Factors to be considered shall include the size, age, condition, habitat, or historical significance of the tree. Trees to be preserved shall be selected early in the project planning process prior to establishing the site layout. Site grading shall be minimized in those areas to prevent damage to the preserved trees. Efforts shall be undertaken to protect the trees during construction.
C. Vegetation in floodplains, steep slopes, and wetlands areas shall remain undisturbed to the greatest extent possible. Any alteration of these areas shall be in conformance with applicable local, state, and federal regulations.
D. Landscape plans shall provide for a mix of evergreen, ornamental, shade trees, and shrubs to provide adequate visual and noise buffer between adjacent land uses. Fences, berms, and other structural features may also be used to provide an adequate buffering between the land uses.
(1) Shrubs shall form a continuous visual screen of at least three feet in height at the time of planting.
(2) Berms shall be at least 2 1/2 feet high and shall have a minimum two to one side slope.
(3) Every 35 linear feet of landscaping shall contain one shade tree and five shrubs. Two ornamental or two evergreen trees may substitute for one shade tree.
E. Perimeter landscapes shall be provided to separate commercial, office, and industrial uses from the street. At least a ten-foot strip shall be landscaped with trees, shrubs, fences, berms or other means deemed acceptable by the Commission.
F. Preservation of existing large trees can be used to reduce new plantings required by this article and the Commission. Existing woodlands can also provide buffers that conform with § 255-1730A.