Soil

A beautiful garden starts with healthy soil. Enhancing your soil is the most important part of good design and planning. To get to know your property’s soil, start with a basic test and analysis, which will reveal nutrient deficiencies, the soil’s pH, and recommendations for amending your soil. Have the test done at a local soil laboratory. The lab will tell you where and how to collect the soil samples to test.

Think of soil as a sponge with pore space containing water, air, mineral particles, and living and dead organic matter. Roots grow in the topsoil layer (topsoil). A good garden soil has uniform texture, neutral pH, and the ability to hold water for root nourishment (water-holding capacity) while allowing excess water to drain (soil permeability).

Soil with a pH of 7 is neutral (neither acid nor alkaline). A pH below 7 is acid and above 7 is alkaline. Along the LA coast, the soil pH is typically 7.5 to 8.5. Soil pH affects nutrient availability. Test your soil to determine its pH. Here are some suggestions for soils that are not neutral:

•	Add lime (calcium carbonate) to acid soil to raise pH (you can use your test lab application rates as a guideline). Acid soil is most common in areas of heavy rainfall, sandy soils, and high organic matter.

Clay, sand, and loam make up the three soil types. Clay has small, thin, disk shaped particles. Sand has large rounded particles and silt particles that are medium sized. Loam is a mix of clay, silt, and sand and is the ideal garden soil. With a combination of large and small pore spaces, it drains well and contains enough air for healthy root growth and nutrient loss is moderate.

To figure out your garden soil type, drench a patch of soil, and then let it dry out for a day, pick up a handful of the soil and squeeze it firmly. If it forms a tight ball and has a slippery feel, it’s clay. If it feels gritty and doesn’t hold its shape (crumbles apart when you open your hand), it’s sandy. If it is slightly crumbly but still holds a loose ball, it’s closer to loam.

Clay soil has little pore space for roots, poor-to-no drainage (encourages nutrient loss), and compacts easily (difficult to dig). Improve soil structure by following these steps:

1.	Work in plenty of organic matter (see soil amendments below) to improve drainage by tilling the amendment about 12 inches deep and top with a good organic compost.

2.	Avoid overhead spray irrigation, where possible. The large droplets of water lead to compaction of the soil and poor drainage.

If these steps fail to improve your clay soil structure, you may need to install a subsurface drain system to carry away excess groundwater. Also known as a French drain, this system consists of lengths of perforated drainpipe which is installed at a slight slope to facilitate drainage in a gravel-filled trench. Wrap the pipe with filter fabric prior to installing it in the gravel. If the perforated holes are on one side of the pipe, be sure to place pipe with the holes pointing down into the gravel.

A hardpan soil layer causes gardeners much grief. Hardpan is created when builders spread excavated subsoil over the soil surface and repeatedly drive heavy equipment over it. A hardpan layer close to the surface may be broken up with these steps:

Sandy soil drains quickly (needs frequent watering), loses nutrients (needs frequent feeding), has deep root growth, and warms quickly in warm weather. Add organic amendments to improve sandy soil.

Organic matter is vital to soil fertility and is especially necessary for clay and sandy soils. Make sure to amend your soil with organic matter because it releases nutrients as it decomposes into humus. Some amendments are great for clay soils to break up the soil to allow oxygen and water to enter the root zone. Below are some successful methods used by landscape professionals in gardens around LA’s coastal cities.

Till in about 11/2 inches of pumice or gypsum and worm castings to the entire area to be landscaped to a depth of 12 inches then top with a good organic compost. Only do this once before planting.

•	Avoid compost with deactivated sludge (solid waste from sewer treatment plants). These typically have high levels of salts and some heavy metals.

•	Avoid manure compost which can also have high levels of salts and can be washed off the garden from sprinklers that overspray or create runoff. This pollution can end up in the ocean.

Vermicomposting, or composting with worms, is a simple, environmentally friendly method of enriching your soil while reusing most kitchen food waste. According to the Natural Resources Conservation Service (NRCS), “two pounds of worms can recycle one pound of kitchen scraps in only 24 hours!”

1.	Start with a plastic storage bin. A 7 cubic foot bin is typically sufficient for a family of six.
2.	Drill several small holes in the bottom for drainage

3.	Cover the holes with a fine mesh (nylon works well) to prevent seepage.
4.	Place bin in moisture-catch tray.

Provide bedding: shredded newspaper, yard clippings, or other organic mulching material. This material should be kept moist but not saturated.

Choose a location for your farm. A dark spot (on the north side of your house) that remains between 55 and 70 degrees Fahrenheit is needed for worm health.

Or call 1-800-CLEANLA to get a worm farm and attend a workshop.

Mulch should not be confused with compost which is a soil amendment. Mulch is used as a top dressing after plants and irrigation have been installed. Mulch covers drip irrigation, keeps the soil cooler, reduces evaporation and makes the garden look neat and tidy.

Fir Walk-On Bark from B.D. However, it is only available in bulk (by the truck load)

* There is no consistency in the industry to the use of the term "walk-on bark." You have to choose on a case-by-case basis. We suggest that you acquire some of one of the two products above and then use it as a basis for comparison for future purchases. You are looking for long, fuzzy shreds with a small amount of flakes and chips; no chunks, no trash, no weeds, no green wood.