§ 33-6.25.6. Acceptable landscape materials and planting practices.

(a)

General standards.

(1)

All landscaping shall be installed in a sound manner and in accordance with accepted standards of the Louisiana Nurseryman's Manual for the Environmental Horticulture Industry, latest edition, which is incorporated herein by reference.

(2)

Where the base or overlay district requires tree preservation, all existing trees to be preserved shall be protected during construction in accordance with section 33-6.27, Tree preservation, of this division.

(3)

Plant material shall be true to name, variety, and size and conform to all applicable provisions of the American Standard for Nursery Stock, latest edition.

(4)

Where palm trees are allowed, they shall be only cold hardy species acclimated to growing in south Louisiana and are subject to the following additional standards:

a.

All palms must have a minimum trunk height of twelve (12) feet at installation, measured from the ground line at the top of the root ball to the base of the heart leaf;

b.

Every two (2) approved palm trees shall equal one (1) tree credit and no credit will be given for Queen Palm or other species of Zone 10 palms.

(5)

Existing preserved, protected and healthy trees may be credited towards the landscape requirements of this section in accordance with subsection (e), Credit, below.

(6)

Each tree shall have a minimum planting area of one hundred (100) square feet and shall be planted at least thirty (30) inches from the edge of any paved surface.

(7)

Where a living fence or hedge row is planted in a setback that is between five (5) feet and seven (7) feet, each parking space abutting the hedge row shall include a wheel stop. The center of each shrub shall be planted at least three (3) feet from the curb or edge of pavement.

(8)

The groundcover required in each landscape area shall form a solid mat or cover the ground within two (2) years of installation. Where grass is provided as groundcover, sod is required.

(9)

Mulch, a minimum depth of three (3) inches, shall be provided within the root zone of trees and shrubs at the time of planting. Mulch must be kept from direct contact with tree trunks and shrub stems. The use of cypress mulch and impervious weed barriers is prohibited.

(b)

Class.

(1)

Class B and Class C trees may be used only to meet landscaping requirements where the planning director determines that special site conditions do not support planting of Class A trees.

(2)

Where the applicant has the option of Class A, Class B, or Class C trees to meet a requirement, a minimum of fifty (50) percent of the site's required trees shall be Class A trees.

(3)

Where Class B or Class C trees are used in place of Class A trees or existing trees are used to meet the requirements of this section in accordance with subsection (e), Credit, below, the ratios in Table 33-6.25.6-1, Tree Ratio by Class, shall apply.

Table 33-6.25.6-1. Tree Ratio by Class

Tree Type	Ratio of Required Trees by Class
Class A	One (1) tree = one (1) Class A tree
Class B	Two (2) trees = one (1) Class A tree
Class C	Two (2) trees = one (1) Class A tree

 

(c)

Species.

(1)

The List of Approved Plant Materials (list) is established and defines the species of trees and shrubs that are allowed to satisfy the landscape and buffer requirements of this section.

(2)

As reflected in the list, all required landscaping shall be comprised of plant materials that are indigenous or acclimated to the growing conditions and climate of South Louisiana.

(3)

New horticultural varieties, cultivars, and species are introduced continuously into the nursery industry, and trees not included in the list may exist in a neighborhood and provide significant tree canopy as well as contribute to neighborhood character. Jefferson Parish encourages consideration of alternate cultivars and species to promote diversity in its urban forest, match existing tree canopy, or maintain neighborhood character. For these purposes, the planning director may make exceptions to the list.

(4)

Any plant material that is listed as prohibited on the list and is proposed to remain or be planted on the site shall not count toward meeting the landscaping requirement. Artificial plant materials and invasive exotic species shall not be used to satisfy the requirements of this section.

(d)

Diversity. Design objectives should be balanced with the need for biological and species diversity. Disease and pest problems that potentially devastate a species make the planting of monocultures undesirable. The following species diversity requirements shall apply based on the number of trees required for the site:

(1)

Development with less than six (6) required trees: No diversity requirement;

(2)

Development with between six (6) and forty (40) required trees: No single species shall comprise more than thirty-five (35) percent of the total number of trees required;

(3)

Development with more than forty (40) required trees: No single species shall comprise more than twenty (20) percent of the total number of trees required.

(e)

Credit. In order to encourage the preservation of existing healthy trees, the applicant may receive credit for an existing healthy tree that is preserved and protected, in accordance with the ratios utilized to calculate credit in Table 33-6.25.6-1.

(1)

Tree credit standard. Existing preserved, protected, and healthy trees may be credited towards the landscape requirements of this section in accordance with Table 33-6.25.6-2, Tree Credit Standard. Trees on the prohibited list and exotic invasive species will receive no credit.

Table 33-6.25.6-2. Tree Credit Standard

Existing Trunk Diameter (DBH) of Preserved Tree(s)	Number of Tree Credits
Each 6 inches or part thereof above 3 inches	1 (equals 1 Class A tree)

 

(2)

In all applicable zoning districts, credit may be applied toward the tree planting requirements of this section by the preservation of existing trees within "property buffer", "streetscape", and "parking lot" landscape areas and other areas of the site left undisturbed by construction.

(3)

Trees preserved in each landscape area shall be credited towards the tree planting requirements of the corresponding landscape area.

(4)

As determined by the planning director, existing or natural vegetation may be used to meet the requirements for a landscape planting area if it provides equivalent planting units, or in the case of a buffer, provides complete screening from the abutting property.

(f)

Size and spacing.

(1)

When they are installed, required plant materials shall comply with the minimum size requirements of Table 33-6.25.6-3, Minimum Size and Spacing at Time of Installation.

(2)

Plant height shall be calculated using the following measurements:

a.

Shrub: From the average grade level of the immediate planting area to the top horizontal plane of the shrub;

b.

Single-trunk tree: From six (6) inches above grade level to the top horizontal plane of the tree, except acceptable palms which shall be measured from the ground line at the top of the root ball to the base of the heart leaf; or

c.

Multi-trunk tree: From the average grade level of the immediate planting area to the top horizontal plane of the tree.

Table 33-6.25.6-3. Minimum Size and Spacing at Time of Installation

Landscape Feature	Minimum Caliper/Container	Minimum Height (Feet)	Minimum Spacing on Center (Feet)
Trees—single-trunk	2 inches	12	25 (Class A) or 15 (Class B) or 10 (Class C)
Trees—multi-trunk	1 inch per trunk, minimum of 3 trunks	10
Shrubs	3 gallon	2	3 for required screening
			N/A for other
Groundcovers (except turf grass)	2.5 gallon	N/A	0.5

 

(3)

Spacing requirements are measured as an average of the number of required plant materials by the length of the street frontage or lot line, as applicable. In no instance shall the distance between trees required as streetscape or property buffer landscaping exceed one hundred (100) feet on center.

(4)

Trees required as streetscape or property buffer landscaping shall be planted in an even, linear spacing. Where the planning director grants a ministerial exception to spacing or alignment, one (1) or both of the following planting installation methods shall be used:

a.

Trees shall be planted in raised planters set at the required spacing and with the following minimum specifications for each planter: height of thirty-six (36) inches from top of curb; area of one hundred (100) square feet; and width of ten (10) feet;

b.

Trees shall be planted in the ground directly adjacent to the required landscape area or servitude to the maximum extent practicable, provided that adequate tree spacing occurs to provide extended tree canopy while maintaining the health of the trees. Where concrete abuts the landscape area or servitude, landscape islands or planting diamonds shall be used along the edge to provide the required spacing of trees.

(5)

Where lines exist or are proposed for utilities or public infrastructure, whether overhead or underground, the exact type, size, or location of trees shall be determined during site plan review.

(Ord. No. 25405 , § 35, 8-9-17)