The key to successful gardening is working with the conditionsin your yard. A well-drained, loamy soil supports most water-wise plants, including those that need a ‘well-drained soil’. Ifyour soil is more sandy or clay, use the tricks below toincrease the range of plants you can grow. Whatever yoursoil’s characteristics, don’t despair - there are likely plantsthat will thrive in it! Getting to Know Your Garden’s SoilIf you have sandy soil: increase the water-holding capacityby creating shallow depressions where water can collect. Soil is a garden’s foundation, providing plants withThese don’t have to be deep – several inches below the rest water, nutrients and beneficial organisms. In western Losof the garden will do. You can grow plants that need a little Angeles County, most soils were deposited by the L.A. Rivermore water in these depressions. Be sure to use a mulch to and its tributaries - or by ancient oceans. Local soils rangedecrease evaporation. And consider using a timer/soil from almost pure sand near the beach to denser claysmoisture sensor to control summer watering – your soil dries further inland. The soil type impacts how you garden, so itout 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 addnutrients 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 tendIf you have clay soil: increase drainage by creating ‘micro- to leach out their nutrients. If your soil is sandy, you’llberms’ (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 plantsthat need good drainage. Be sure to check soil moisture (at Clay soils - have smaller soil particles that retain watera depth of 3-4 inches) before watering. If you have a clay and soil nutrients better. They also tend to drain morelayer, consider drilling holes through it. If you have very poor slowly, which can create problems for some water-wisedrainage, 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 innatures-backyard.blogspot.com/. You can e-mail your Garden Soil Mother Nature’s Backyard has old bricks, asphalt, chunks ofquestions to: firstname.lastname@example.org 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.
Two simple tests will help you determine your soil’s physical Percolation (perc) Test – for soil drainagecharacteristics: 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 withtypes 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 layerliving.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 canFill a large glass jar (1 quart or larger) 1/3 full with soil. Fill often detect a dense layer by digging down until you cannotthe jar almost to the top with water. Cap securely and shake dig further. A depth of less than 20 inches means you havewell; then let the layers settle out. Mark the line of sediment a shallow soil. You may want to break up the imperviousthat 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 seesome darker brown material on the top (or still floating on Soil pH – influences the availability of soil nutrients to yourthe water). This is the organic (or humus) material, made plants. Most local soils have a pH from about 6.5 to 8.0; anup of old leaves and roots. Humus is good for plants. ideal soil for many plants is around 7.0. If you are havingThe picture above will help you determine your basic soil difficulty getting plants to grow – or if you want to planttype. In general, loam soils (including sandy loams & clay ‘acid-loving’ plants - you can test your soil pH with a simpleloams) 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 lowbe ‘for sandy soils’ but many local native plants like sandy fertilizer needs; other plants (including vegetables) havesoils. Clays are often excellent garden soils, as long as they higher nutrient needs. Simple test kits that indicate levels ofhave adequate drainage. You’ll want to conduct a percolation the basic nutrients (nitrogen; potassium; phosphorus) aretest (next page) to check your soil’s drainage. available at most garden centers.