Landscape Landscape
Soil Amendments & Mulch - Design

What are soil amendments?

A soil amendment is any material added to a soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration and structure. The goal is to provide a better environment for roots.

Properly selected soil amendments can go a long way towards achieving our goal of establishing beautiful, successful, low-water use landscapes. For this reason, as part of the City's Landscape and Irrigation Standards, soil amendments shall be added based upon soil analysis results and recommendations performed by a soil laboratory.  A soil report is required on the landscape planting plan. Soil reports, analysis, and recommendations are critical to establishing new plant material.

Examples of a typical  Soil Analysis pdf  and  Soil Recommendation pdf


A minimum two inch (2”) layer of mulch must be applied on all exposed soil surfaces, except in areas covered by groundcovers, and no mulch shall be applied within twenty-four inches (24”) of the base of trees. So what is mulch exactly?

As defined as by 8.108.090 SMMC, mulch is  “Any organic material such as leaves, bark, wood chips, straw, compost, or inorganic mineral materials such as rocks, gravel, and decomposed granite left loose and applied to the soil surface for the beneficial purposes of reducing evaporation, suppressing weeds, moderating soil temperature, and preventing soil erosion.”
Adding soil amendments
Mulch around plants
Last updated: Monday, 08/09/2010


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