Mulching trees and shrubs is a good practice in keeping plants healthy and reducing landscape maintenance. Mulch helps conserve about 10 to 25 percent of the moisture lost from plants through evaporation and helps to keep the soil well aerated by reducing soil compaction that results from heavy rain. Mulch can also reduce water runoff and soil erosion as well as the likelihood of soil borne pathogens. Organic mulches decompose with time releasing small amounts of nutrients and organic matter into the soil. They help maintain a more uniform soil temperature (warmer in the winter and cooler in the summer) and provides an environment for beneficial soil microorganisms and earthworms.
Mulch serves its function best at a depth fo 2-4 inches and should be kept 1 to 2 inches from the base of plants to prevent bark decay. Keep in mind that mulch depth can depend on the type of material used and the drainage and moisture holding capacity of the soil. Sandy soils dry out quickly and often benefit from a slightly deeper mulch layer (3 to 4 inches). A site that stays moist may not benefit from mulching at all.
Mulch can be applied any time of the year, however the best time to mulch is late spring after the ground has thawed and the soil has warmed. Mulching while the ground is still cold can delay soil warming and possibly inhibit plant growth. When fertilizing it is not necessary to remove the mulch as the nutrients will penetrate through the soil each time you water.
Practice good soil maintenance. Signs of plant stress could signal soil lacking in essential nutrients or components. A simple soil test can help to remedy this problem. Generally acidity of a soil can be controlled by adding lime to make it more basic or aluminum sulfate to increase acidity. Research the types of plants you have in order to determine the environment which is suitable.
Most evergreen trees and shrubs prefer a slightly acidic soil while many deciduous shrubs and perennials do not. Adding the same fertilizer to an entire garden can benefit some plants but can actually inhibit the absorption of nutrients in others. Ask your local garden center for advice on feeding your trees, shrubs and perennials.
