What Types of Materials Can You Mix Directly Into Garden Beds?

Ideal Soil

• According to the Utah State University extension, the ideal soil composition is deep, fertile, well-drained, near neutral (pH), and has a lot of decayed organic matter. Most soils are classified as clay, sandy, or humus (soil rich in organic matter) . Adjustments are needed to maintain an ideal balance of 40 percent sand, 40 percent humus and 20 percent clay.

General Additives

• As the ideal soil composition rarely occurs naturally, additives are necessary in almost every garden. Almost all gardens benefit from the addition of organic material. Add a 2- to 3-inch layer of organic matter and incorporate it 6 to 8 inches deep. This will increase the water-retention capacity and structure in sandy soils, and will lighten clay soils. Good sources of organic material are leaves, grass clippings, manure, straw and twigs.

Ph Adjusters

• As a neutral pH is desired, adjustments may be necessary to increase or lower pH. For garden soils with a high pH (alkaline), add organic matter such as peat moss or sawdust. Chemicals like iron sulfate and sulfur also help lower pH. Add lime or dolomite to increase pH and reduce acidity. Once the balance is achieved, gypsum is the ideal additive as it is neutral.

Composting

• Humus, Latin for "soil," often refers to the components of soil rich in organic materials. Composting creates a black, soil-like material rich in humus. Rather than purchasing at a garden center, create a compost pile in the backyard. Layer ingredients rich in carbon (fallen leaves or wood waste) and nitrogen (greener materials like grass clippings) to create compost. Be sure to add fertilizer or animal manure to accelerate the start of the pile. Once added to the garden, compost gives plants the nutrients they need to thrive.

Timing

• Gardeners are always eager to get started. Damage to the soil structure is a risk when impatient gardeners start tilling-in additives too soon. Test your soil for readiness by taking a handful, squeezing it in your palm and dropping it on a sidewalk. If the ball shatters into small clumps, go ahead and till. If it holds firm, allow the soil to dry another week or two. If the ball will not form in your hand, water the area thoroughly and wait a day or two to test again.