San Marcos Design Manual (March 16, 2021)

D A PP E ND I X

Planting Guidelines

Section D.1.2.4 Recommended Standards for Cutouts in Sidewalks A. General. Cutouts in Sidewalks should be appropriately sized to reduce conflict with hardscape and tree growth. Tree trunks do not grow necessarily in a concentric manner evenly on all sides. The trees root flare grows wider and the tree grows in diameter. B. Sub-Base Material Recommendations. Sub-base material under sidewalks should be 6 inches of washed gravel. This should prolong the life of sidewalks. Other Sub-base materials such as sand, limestone, or none tend to allow roots to grow directly under the slab in the sub-base material.

Section D.1.2.5 Mulch Recommendations

A. Organic mulches. Include wood chips, pine needles, shredded bark, nut shells, compost mixes and leaves. Organic mulches decompose at different rates, depending on the material, and periodically must be replenished. B. Compost. Composted wood chips make good mulch, especially when the leaves, bark and wood are included in the composition. Fresh wood chips also may be used around established trees and shrubs. Avoid using uncomposted wood chips that have been piled without exposure to oxygen. Sawdust, grass clippings and straw are not recommended. C. Inorganic Mulches. Include decorative stone, lava rock, pulverized tires and geotextile fabrics. Inorganic mulches are useful in xeriscaping and for soil protection in high traffic areas, but are not recommended for mulching around trees. Heat reflected from inorganic mulches may be high enough to kill thin-barked trees. Section D.1.2.6 Irrigation Recommendations A. Established trees can be damaged from the installation of irrigation in the landscape either by trenching or poor design. B. The following irrigation methods are recommended for newly planted trees: 1. Trees less than 1.5” in diameter or smaller shall be provided with a minimum of one bubbler. 2. Trees 1.5” to 2.5” in diameter at shall be provided with a minimum of two bubblers.

C. Alternative materials are recommended to use within cutouts to tree grates: 1. Modular paver blocks, low 6 inch tall fence, low wall or curb, thin layer of mulch not touching the trunk, landscape plants, washed gravel without fines, or washed rock may be used; no extra fill soil shall be placed on top of the root ball or cover the root flare. 2. Paver blocks and tree grates must be adjusted on a regular basis or they can kill the tree if they are not maintained.

Good Example

Good Example

Good Example

D:5

Amended: March 16, 2021 San Marcos Design Manual