Mushroom compost. A good source of nutrients when mixed with other materials. Source of large amounts of alkalinity and sometimes salts.
Peat moss. Compacts easily due to fine texture and dries out quickly. Not recommended as a top dressing because water will not penetrate when dry.
Pine boughs. This is a good covering for perennials in the winter.
Pine needles. Not widely available and should be mixed with other materials unless soil acidity is desired.
Shredded leaves. Leaves are variable in texture and can be collected and shredded at home. Mix into the soil in the fall and allow to break down naturally during the winter for improved soil quality.
Straw. Coarse-textured so it persists a long time, but can blow away easily unless mixed with other materials. Generally not suitable as a landscape mulch, but provides winter protection and cover for grass seed.
Spread mulch under trees, shrubs and throughout planting beds to a recommended depth of 3 to 4 inches for medium- to coarse-textured materials.
Pull mulch away from the bases of tree and shrub trunks creating a doughnut hole. Do not pile it up against the trunk ("volcano mulching"). Excessive mulch on the trunk causes moisture to build up, creating ideal conditions for insect pests, diseases and decay.
Ideally, the mulched area around a tree should extend to the drip line of the branches, or at least cover a 4- to 5-foot diameter area around the trunk. The larger the mulched area, the more beneficial.
Check mulch depth annually and replenish as necessary.
Mulch provides an insulation layer. Mulched soils are warmer in winter and cooler in summer than bare soils. Roots are protected from temperature extremes, creating less freezing and thawing of the soil in winter, which can heave and injure plants.
Reach Sara Busse at sjbu...@gmail.com.