This brochure is one of the educational resources provided by Mother Nature’s Backyard – see http://mother-natures-backyard.blogspot.com/

1. The key to successful gardening is working with the conditions
in your yard. A well-drained, loamy soil supports most water-
wise plants, including those that need a ‘well-drained soil’. If
your soil is more sandy or clay, use the tricks below to
increase the range of plants you can grow. Whatever your
soil’s characteristics, don’t despair - there are likely plants
that will thrive in it!
Getting to Know Your Garden’s Soil
If you have sandy soil: increase the water-holding capacity
by creating shallow depressions where water can collect. Soil is a garden’s foundation, providing plants with
These don’t have to be deep – several inches below the rest water, nutrients and beneficial organisms. In western Los
of the garden will do. You can grow plants that need a little Angeles County, most soils were deposited by the L.A. River
more water in these depressions. Be sure to use a mulch to and its tributaries - or by ancient oceans. Local soils range
decrease evaporation. And consider using a timer/soil from almost pure sand near the beach to denser clays
moisture sensor to control summer watering – your soil dries further inland. The soil type impacts how you garden, so it
out quickly! If you want to grow vegetables, consider adding pays to learn more about your garden’s soil.
compost to your vegetable garden soil. This will add
nutrients while increasing the soil’s ability to hold water.  Sandy soils - have larger soil particles that allow them
to drain well. They also dry out more quickly and tend
If you have clay soil: increase drainage by creating ‘micro- to leach out their nutrients. If your soil is sandy, you’ll
berms’ (areas 1-2 ft higher than the rest of the garden), need to water more frequently in summer.
slopes or raised beds. These will allow you to grow plants
that need good drainage. Be sure to check soil moisture (at  Clay soils - have smaller soil particles that retain water
a depth of 3-4 inches) before watering. If you have a clay and soil nutrients better. They also tend to drain more
layer, consider drilling holes through it. If you have very poor slowly, which can create problems for some water-wise
drainage, consider gardening in containers or raised beds. plants. If your soil is clay, you’ll need to water less
frequently to avoid over-watering.
Learn more about soils at:
Urban soils are complex, reflecting their human
 http://websoilsurvey.nrcs.usda.gov/app/ occupation. Depending on where you live, your garden may
 http://www.rain.org/global-garden/soil-types-and-testing.htm once have been a farm or ranch – or even had a factory on
 http://en.wikipedia.org/wiki/Soil_classification it! Your soil may have been compacted by heavy equipment
or be composed of fill dirt brought in from somewhere else.
Learn more about water-wise gardening at: http://mother- It may even include ‘buried treasure’ (for example, the soil in
natures-backyard.blogspot.com/. You can e-mail your Garden Soil Mother Nature’s Backyard has old bricks, asphalt, chunks of
questions to: mothernaturesbackyard10@gmail.com cement and other debris dumped since the 1940’s).
The more you know about the unique characteristics of
your soil, the better you can match plants and watering
methods to your soil conditions. Turn the page for some
ways to learn more about your garden’s soil.

2. Two simple tests will help you determine your soil’s physical Percolation (perc) Test – for soil drainage
characteristics: the sedimentation and percolation tests.
Dig a hole 1 ft deep by 1 foot across.
Simple sedimentation test (if you have several different Fill with water – let it drain. Fill with
types of soil, you’ll want to do this test for each type) water again and note how long it takes
to drain completely.
Soils that drain within ½ hour are very
well-drained. Native plants needing
sandy soils will thrive in very well-
drained soils. Soils that drain in less
than 3 hours are well-drained. Well-
drained soils are ideal for most water-
wise plants, vegetables, trees and
shrubs. You are very lucky if you have a well-drained soil.
Soils that take more than 6 hours have poor drainage. You
will need to monitor your soil’s moisture carefully so you
don’t over-water. If you want to grow plants that need good
drainage, you’ll need to create berms (see next page) to
improve drainage. You’ll also want to check your soil depth.
http://www.small-farm-permaculture-and-sustainable- Soil depth – some poorly drained soils have a dense layer
living.com/sustainable_soil_structure_management.html that keeps water from draining. This may be a true
‘hardpan’, a rock layer or just a compacted zone. You can
Fill a large glass jar (1 quart or larger) 1/3 full with soil. Fill often detect a dense layer by digging down until you cannot
the jar almost to the top with water. Cap securely and shake dig further. A depth of less than 20 inches means you have
well; then let the layers settle out. Mark the line of sediment a shallow soil. You may want to break up the impervious
that settles at 2 minutes (sand particles); 2 hours (silt layer (or drill holes through it) to improve drainage.
particles) and 24 hours (clay particles). You may also see
some darker brown material on the top (or still floating on Soil pH – influences the availability of soil nutrients to your
the water). This is the organic (or humus) material, made plants. Most local soils have a pH from about 6.5 to 8.0; an
up of old leaves and roots. Humus is good for plants. ideal soil for many plants is around 7.0. If you are having
The picture above will help you determine your basic soil difficulty getting plants to grow – or if you want to plant
type. In general, loam soils (including sandy loams & clay ‘acid-loving’ plants - you can test your soil pH with a simple
loams) are good for growing just about anything. Very test kit (available at most garden centers).
sandy soils may require plants that are specifically noted to
Soil basic nutrients – California native plants have low
be ‘for sandy soils’ but many local native plants like sandy
fertilizer needs; other plants (including vegetables) have
soils. Clays are often excellent garden soils, as long as they
higher nutrient needs. Simple test kits that indicate levels of
have adequate drainage. You’ll want to conduct a percolation
the basic nutrients (nitrogen; potassium; phosphorus) are
test (next page) to check your soil’s drainage.
available at most garden centers.