Chapter 10 Tree Canopy, Landscaping and Open Spaces Part 4 Implementation Standards Page 1 of 2

10.4.1 Plant Species

Any proposed new plant material used to satisfy the requirements of this development code shall be of a species other than those listed in the current version of the Louisville and Jefferson County Prohibited Plant List adopted by the Planning Commission. To the greatest extent possible, new plant material should be selected from species included in the current version of the Louisville and Jefferson County Preferred Plant List adopted by the Planning Commission. This list consists of species that are either native to Jefferson County or that perform particularly well in the area, or both.

Over-dependence on a single genus may result in extensive loss due to disease, insects or other pests. To ensure a diversity of species within Louisville and Jefferson County’s forests the mix of required trees and shrubs for all development proposals shall conform to the following diversification formula:

Exceptions to the diversification formula shall be allowed for:

1. Sites of less than two acres, if required plantings are chosen from the Preferred Plant List
2. Sites located within a Neighborhood Study or Corridor Study approved by the Planning Commission with street tree or landscape guidelines or sites containing a streetscape master plan approved by the Planning Commission;
3. A Planned Development or General Development Plan containing a planting plan approved prior to the effective date of this code

10.4.2 Plant Quality

All plant materials shall be living plants (artificial plants are prohibited.) Plant materials shall conform to the standards of the American Association of Nurserymen and shall have passed any inspections required under state regulations. Bare root plants, with the exception of vines and groundcovers shall be prohibited.

10.4.3 Plant Sizes

All required plant material shall meet the following size criteria at time of installation:

Size criteria for deciduous tree species shall be determined based on its Size Type as described in Chapter 1 Part 2 (Definitions) of the Land Development Code. Installation criteria for each Size Type is as follows:

When planting Medium or Large Trees, Small Sites (as defined in 10.2.2(C) and Single Family Residential sites shall be required to install such trees at a minimum size of 1 inch caliper.

All minimum size requirements shall conform to the characteristics set forth in the American Standard for Nursery Stock, latest addition.

Any existing trees on a site or street trees planted on an adjacent right-of-way that are used to meet the Tree Canopy Regulations (Chapter 10 Part 1) may be credited towards fulfillment of any landscaping, screening, or buffering provisions of this Chapter. The following criteria shall be used where existing healthy trees are being preserved and substituted for newly planted trees:

1. An existing 6 inch-12 inch caliper tree, surrounded by a minimum of 133 square feet of landscape area, may be substituted for two (2) new trees of the required minimum size
2. An existing 12 inch-24 inch caliper tree, surrounded by a minimum of 250 square feet of landscape area, may be substituted for three (3) new trees of the required minimum size
3. An existing tree greater than 24 inch caliper, surrounded by a minimum of 300 square feet of landscape area, may be substituted for four (4) new trees of the required minimum size

10.4.4 Spacing

No newly planted trees may be planted closer together than 10 feet for small trees, 25 feet for medium trees, and 30 feet for large trees. When planting new trees near existing mature trees, leave a minimum distance of half of the new tree’s mature spread between the new tree and the existing trees. Planning Commission staff can authorize a closer spacing of trees in special circumstances.

Table 10.4.1

No tree shall be planted in a space less than 3 feet in width. Only small trees shall be planted in spaces less than 4 feet in width.

Trees shall be located to provide shade over impervious surfaces to the maximum extent possible.

Figure 10.4.1

No tree shall be planted closer than 5 feet to any fireplug, utility pole, or similar utility structure. Large or medium trees shall not be located beneath overhead wires, and shall be planted at least 20 feet from any easement or right-of-way in which overhead wires are located. With approval from the appropriate utility company Type C trees planted 30 feet on center may be planted beneath overhead utility lines to meet perimeter tree planting requirement.

No landscape material shall be planted closer than 5 feet from the sides of any electric transformer box and all landscape material shall be planted a minimum of 10 feet from the door of such boxes.

Overhead Wire Graphic

To assure that landscape materials do not constitute a driving hazard, a “sight triangle” will be observed at all street intersections including street intersections and intersections of alleys or driveways as illustrated below. The sight triangle shall be measured from edge of pavement to edge of pavement.