What Plants Can I Put Cedar Mulch Around?

Cedar mulch is used around plants to conserve water, control weeds and improve soil condition. Cedar, whether shredded or chipped, resists decay. Easy to apply, cedar is long-lasting mulch used on perennial or mature plants. Because cedar is slow to decompose, it is rarely used around vegetables or annual bedding plants that need seasonal nutrition.

Cedar mulch inhibits weeds by smothering germinating weed seeds. The mulch blocks sunlight from the seeds so that they do not mature as weeds. Typically cedar mulch contains bark, wood and leaves. These ingredients decompose at different rates, adding nutrients to the soil at a gradual rate. This benefits perennial flowers, shrubs and trees. Cedar insulates the soil and plant roots against temperature extremes of heat and cold. The wood mulch diffuses rain drops and minimizes root washout and soil erosion. Cedar fragrance discourages many insects and acts as a natural repellent to moths, cockroaches and ants.

Use cedar mulch in landscape beds around perennial flowers and shrubs. If soil is poor and immediate nutrients are desired, make a mulch sandwich. Apply a layer of compost or other rich organic materials directly to the soil. Add cedar mulch over the fertilizer layer. The top layer of shredded or chipped cedar protects the compost from wind or water erosion.

Spread cedar mulch under trees for slow-release nutrients and water conservation. Apply the mulch in an even layer from the drip line to about 6 inches from the tree trunk. Piling cedar or other mulch against the tree trunk encourages fungus, borers and wood rot.

Cedar mulch fades to gray as it ages. This appearance is unsightly in some urban areas and ornamental gardens. Reapply a top layer as needed for a fresh look. Cedar mulch decomposes over years, sometimes taking up to 10 years to decay. Think of it as long-term mulch, not a quick organic meal for plants. Some gardeners find that wood chips such as cedar are nitrogen hogs. Mixed into vegetable garden soil, fresh wood chips tie up nitrogen that otherwise benefits vegetable growth. Cedar and other wood chips mixed into the soil create a nitrogen imbalance that can impede seed germination. The preferred use of cedar mulch is around perennials with established root systems.

Cedar mulch and wood chip mulches reduce water evaporation by as much as one-half. When a thick layer of cedar mulch is applied over clay or moist soils, it can prevent beneficial water evaporation. Excessive water trapped by the mulch causes root rot. Thick cedar mulch also provides protective cover for invasive pests such as voles. Watch for rodent activity under cedar mulch and other wood-chip ground covers.