Growing
Healthy Soil
Healthy Soil
Healthy Soil
An Investment In Your
Garden
Did you know that by simply improving your soil, you can beautify your garden, cut your water bill, improve water quality in our streams, and even reduce your work? Growing healthy soil — and a healthy garden — is as easy as adding compost and other organic amendments to your soil. In fact, this is the single most important thing you can do for your garden.
“Compost” is the dark, earthy material naturally produced by decaying plants and animal wastes. This mix of living and dead organic matter supports an intricate web of soil life, which in turn keeps your soil loose, moisture-holding, fertile and well-drained. The following three steps for growing healthy soil are explained in this factsheet:
- Before planting, amend the soil throughout the entire planting area with compost.
- Mulch existing plantings with compost, leaves, grass clippings or woody mulches.
- When you need to feed plants, use natural organic and slowrelease fertilizers.
Understand Your Soil
“Dirt” is the mineral portion of the soil that supports plants, supplies nutrients and stores water. There are three general types of soil, determined by the size of the soil particles. These affect how the soil functions. You may have more than one kind of soil in different areas of your garden.
Sandy soils contain large particles which are visible to the naked eye. They feel gritty and will not form a ball when squeezed in your hand. Sandy soils are loose and drain easily, but do not store water or nutrients for plants. Clay soils are made up of tiny particles that feel sticky when wet, and dry into dense chunks or fine powder. They hold nutrients and water well, but drain poorly. Loamy soils are a mix of sand, clay and organic matter. When squeezed in your hand, moist loam forms a ball which crumbles when poked with a finger. Loamy soils are generally loose, well-drained and able to store moisture and nutrients. Air and water are essential elements that transport nutrients to plants and carry away waste. Together, they make up half the volume of healthy soil. Compacted or heavy clay soils may not have adequate space for air and water to move freely to plant roots. Organic matter and soil life make up just a small part of the soil volume, but are the glue that holds healthy soil together. Decomposing plant materials (like compost) support a great variety of beneficial organisms ranging from microscopic bacteria to earthworms. Organic matter and soil life keep plants healthy by:
• fighting plant diseases and pests.
• storing fertilizers and natural nutrients for gradual release, while preventing them from washing into streams.
• storing water, which reduces runoff and your garden’s irrigation needs.
• making clay soils better drained and easier to work.
• trapping and breaking down pesticide residues and
• polluted runoff.
• Think twice before using pesticides that may damage
• soil life.
• Don’t overfertilize: more is not better.
• Don’t overwater: overwatering can promote plant
• disease and exclude air from roots.
• Prevent soil compaction. This means walking on
garden beds as little as possible, keeping heavy equipment and cars off lawns, and minimizing the use of rototillers. Excessive use of chemicals, overwatering and soil compaction can harm beneficial soil organisms and reduce their ability to keep soil healthy.
Mulch your Plantings
"Mulch" refers to a material placed on the soil’s surface. (Although usually organic, mulches can also be products such as landscape fabric.) Mulches reduce evaporation, limit weed growth, minimize soil temperature fluctuations, and limit soil runoff that can choke streams and fish. Most mulch products provide these benefits, but organic mulches — such as compost or bark — can be especially beneficial because earthworms and other soil life gradually break them down, mixing them into the soil to nourish plants.
When
• Apply annually or as needed.
• Mulch in early summer to conserve moisture, feed plants and prevent weed seeds from sprouting.
• Mulch in fall to protect soil from erosion, smother weeds and retain warmth.
Where
• Mulch annual and perennial planting beds, as well as the surface of container plantings.
• Cover entire tree and shrub planting beds, or make mulch rings at least 3 feet wide around each plant in lawns.
• Keep mulch a few inches away from stems, crown and trunks to prevent rot and pest damage.How
Remove weeds and grass before spreading mulches. Use porous weed barriers such as woven landscape fabric or cardboard to smother aggressive perennial weeds before mulching.
How Much
• Grass clippings: 1/2 to 1 inch deep Compost, leaves, sawdust, medium- or fine-ground bark: 1/2 to 2 inches deep
• Coarsely shredded bark, wood chips or tree trimmings: 2 to 4 inches deep
Note: One cubic foot of mulch covers 12 square feet 1
inch deep.One cubic yard will cover 324 square feet 1
inch deep, or 108 square feet 3 inches deep.
Fertilize Moderately and Responsibly
Fertilize moderately with natural organic and slow-release fertilizers to grow healthy, easy-to-maintain plants. Too much fertilizer can produce excess growth that is easily damaged by pests, wind, frost and drought. Many of the nutrients in quick-release fertilizers may wash off to pollute lakes, streams and groundwater. Most established trees and shrubs do not need regular fertilization. Mulching can provide all their nutrient needs in most cases. Even heavy feeders like roses, annuals and flowering perennials take in adequate nutrients through yearly compost applications.
When choosing a fertilizer, look for the words “natural/organic” or “slow-release” on the fertilizer bag. Though these fertilizers may cost more, they offer better value and greater protection of water quality as more of their nutrients actually feed plants, instead of washing into streams or groundwater. “Natural organic fertilizers” include rock phosphate and other minerals, plant products such as alfalfa meal, as well as animal byproducts like bone or fish meal. Most nutrients in natural fertilizers must be digested by bacteria before they dissolve in water and plants can use them. These nutrients are slowly released when warm soil stimulates the bacteria, which is when they are needed by actively growing plants.
“Slow-release fertilizers” such as sulfur-coated urea become available as outer coatings are dissolved by moisture and soil bacteria when plants are actively growing. “Quick-release fertilizers” like urea and ammonium sulfate quickly dissolve in water. They wash through the soil with rain or irrigation if not immediately used by plants or absorbed by organic matter
• Grass clippings: 1/2 to 1 inch deep Compost, leaves, sawdust, medium- or fine-ground bark: 1/2 to 2 inches deep
• Coarsely shredded bark, wood chips or tree trimmings: 2 to 4 inches deep
Note: One cubic foot of mulch covers 12 square feet 1
inch deep.One cubic yard will cover 324 square feet 1
inch deep, or 108 square feet 3 inches deep.
Fertilize Moderately and Responsibly
Fertilize moderately with natural organic and slow-release fertilizers to grow healthy, easy-to-maintain plants. Too much fertilizer can produce excess growth that is easily damaged by pests, wind, frost and drought. Many of the nutrients in quick-release fertilizers may wash off to pollute lakes, streams and groundwater. Most established trees and shrubs do not need regular fertilization. Mulching can provide all their nutrient needs in most cases. Even heavy feeders like roses, annuals and flowering perennials take in adequate nutrients through yearly compost applications.
When choosing a fertilizer, look for the words “natural/organic” or “slow-release” on the fertilizer bag. Though these fertilizers may cost more, they offer better value and greater protection of water quality as more of their nutrients actually feed plants, instead of washing into streams or groundwater. “Natural organic fertilizers” include rock phosphate and other minerals, plant products such as alfalfa meal, as well as animal byproducts like bone or fish meal. Most nutrients in natural fertilizers must be digested by bacteria before they dissolve in water and plants can use them. These nutrients are slowly released when warm soil stimulates the bacteria, which is when they are needed by actively growing plants.
“Slow-release fertilizers” such as sulfur-coated urea become available as outer coatings are dissolved by moisture and soil bacteria when plants are actively growing. “Quick-release fertilizers” like urea and ammonium sulfate quickly dissolve in water. They wash through the soil with rain or irrigation if not immediately used by plants or absorbed by organic matter