OUTDOOR FEATURES
Soil Manage
Mulching
*
Optional Water Efficiency Measure: May contribute to the 30 percent water efficiency requirement,
depending on the chosen WaterSense® Approved Certification Method (WACM).
ilk
ITI
UNDERSTAND
Healthy soil helps cycle nutrients, minimize runoff,
retain water, and absorb excess nutrients,
sediments, and pollutants.
Local jurisdictions may have post-construction soil
management requirements as part of their
storrnwater management programs.
Soil characteristics such as pH and composition
can help determine appropriate plant choice for a
water-efficient ya rd.
Slopes can be challenging because of the potential
for erosion and runoff, if slopes cannot be avoided,
consider installing plants with deeper root zones,
such as native groundcovers and shrubs, to
provide stabilization and prevent erosion. Ensure
that appropriate plantings are used, and that only
irrigation methods suitable for slopes are applied.
Soil amendments can be organic or inorganic. They
are mixed into the soil and help the soil retain
moisture so that less irrigation is needed. As a
result, soil amendments can result in short- and
long-term water savings and improve plant health.
Mulch can also be organic or inorganic. Organic
mulches include wood-based materials such as
wood chips, while inorganic mulches include rock-
based materials such as pea gravel or lava rock.
Mulching prevents water from evaporating from the
soil and, in the case of organic mulch, decays and
improves soil health over time.
BUILD
RETAIN and protect native topsoil and vegetation where practical. If soil needs to be removed,
stockpile and reuse it to restore disturbed soils.
MINIMIZE soil compaction during the construction phase. Soil can become compacted during
construction from equipment and foot traffic. Aerate soil with a lawn aerator to increase the infiltration
Benefits of Mulching
The benefits of mulching for maintaining healthy
soil include:
•	Preventing loss of water from the soil by
evaporation. Moisture moves to the surface
and evaporates if the soil is not covered by
mulch.
•	Maintaining a more uniform soil
temperature. The mulch acts as an insulator
that keeps the soil cool under intense
sunlight and warm during cold weather.
•	Preventing crusting of the soil surface.
Mulch improves absorption and percolation
of water into the soil and reduces erosion.
•	Improving soil structure. If using organic
material for mulch, as it decays, the material
becomes topsoil and can also add nutrients
to the soil.

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of water into the ground, thus improving water flow
to the plants' root zones and reducing water
runoff. See the Sustainable Development Code
web page at
https://sustainablecitycode.org/brief/reduce-soil-
compaction-during-construction-2/ for more
information on reducing soil compaction during
construction.
COLLABORATE with the landscape professional to
ensure that any steep slopes are planted correctly.
Choose plant types that will hold onto the soil, and
be mindful of irrigation system design, if
applicable. Work with the landscape professional to ensure that any material placed on the slope will
not move over time. This guidance primarily applies to slopes greater than four feet of horizontal run per
one foot of vertical rise (4:1, 25 percent or 14 degrees).
APPLY two to three inches of mulch to non-turf landscaped areas, such as those with shrubs, trees,
annuals, perennials, and/or groundcover. Avoid piling mulch against the stems of plants or the trunks
of trees to prevent rot.
AVOID using rock mulches in sunny areas or around non-arid climate plants, as they radiate large
amounts of heat and promote water loss that can lead to scorching.
Soil Test Kit
To determine soil health, the builder or
homeowners can have their soil tested for
nutrient content, pH, soil composition, and
organic matter content. Contact a local
Cooperative Extension Office at
www.nifa.usda.gov/land-grant-colleges-and-
universities-partner-website-
directory?state=All&type=Extension or state
university for a soil test kit or soil testing services.
= | VERIFY
CONFIRM that the soil has not been compacted
from construction activities by ensuring that the
soil is soft enough to push a shovel in and that
there are no signs of pooling or puddling of water in
low areas.
VERIFY that steep slopes are covered or planted
appropriately to ensure stability. This primarily
applies to slopes greater than four feet of
horizontal run per one foot vertical rise (4:1, 25
percent or 14 degrees). Verifiers can measure the
grade of slopes with tools such as a laser level or
clinometer.
MEASURE the depth of mulch in landscape beds
using a ruler or tape measure.
Learn More
Go to WaterSense's Landscaping Tips web page
at www.epa.gov/watersense/landscaping-tips to
learn more about strategies to improve and
maintain soil health.
The Sustainable Technologies Evaluation
Program also maintains a guide for preserving
and restoring healthy soils during construction at
https://sustainabletechnologies.ca/home/urban-
runoff-green-infrastructure/healthy-
soils/preserving-and-restoring-healthy-soil-best-
practices-for-urban-construction/.
*NOTE: Consult with the Home Certification Organization for specific verification protocols.

This technical fact sheet is part of EPA's Technical Reference Manual for
WaterSense Labeled Homes. For the full document and other tools and
resources for homes, visit www.epa.gov/watersense/tools-and-resources
EPA-832-F-23-016
July 2023

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