Mulch's are organic material's that are layered on top of garden beds, around trees, shrubs, and other plants. There are a number of types available with different characteristics. They are readily available in bags or bulk delivered, are inexpensive, and come in different colors and textures.
Some can be made or obtained for free from a number of sources. They can be decorative or serve the multiple purpose of acting as a nutrient source as well as conserving soil moisture and suppressing weed growth.
THE FUNCTION OF MULCHES
Proper usage of the right kind of mulch can eliminate or at least significantly reduce weeding, lower the amount of water required, and generally helps to maintain a healthy garden. Mulch retains moisture and protects your soil from drying out, slowly releasing it into the soil for use by your plants. A steady, gradual supply of moisture provides a stable growing environment and supports a healthy variety of soil organisms. Mulches also protect the soil from temperature variations and help to insulate the root zone from extremes of heat or cold.
Another benefit is the mulch protects the soil from erosion and crusting over. This allows for better air and water penetration creating a looser soil
TYPES OF MULCHES
Decorative mulch types include: Bark chips or chunks, wood chips, shredded cedar, cocoa shells, and pine needles.
These are long lasting products that decompose very slowly. They add little to the fertility of the soil and are best suited to ornamental beds.
There are also materials like recycled plastic tree rings or decorative gravel that may be used in xeriscaping or rock garden situations.
Some other types of mulches that are more rapidly decomposed are: Shredded leaves, leaf mold, grass clippings or straw. These are best suited to vegetable plots and can be turned into the soil at the end of the season adding to the percentage of organic matter in the soil improving it's structure. Soils high in organic matter encourage root development and biological activity, further enhancing soil structure.
Mulched soils need less cultivation than bare soils. It is believed that soil structure and biological activity can be improved in some ways by reducing tilling/cultivation. Sound application of mulch allows for this. These type mulches can be used on ornamental beds as well but would need to be replaced more often.
SELECTING THE RIGHT MULCH
Mulch needs vary by season, climate zone and application. An ideal mulch should be economical, readily available, and easy to apply or remove. It should stay in place, supply some nutrition to the soil, and be free of weeds. It should also not be a harbor for insects or disease.
Many folks use plastic or spun fiber weed block fabrics under the mulch. There are some pro's and cons to this. The plastic helps to warm the soil in spring but may also cause it to become too hot in summer injuring plant roots.
Thick layers of materials like wood chips serve as...