Coast Gardener
Winter mulching
Coast Gardener Newspaper and Web Column - October 20, 2008
Mulching landscape beds is certainly important during the active growing season. It helps to maintain soil moisture, moderate soil temperatures, and acts as a weed barrier layer.
Mulching is also a significant activity to help ensure winter survival of tender landscape plants. After plants have gone dormant and the ambient temperatures have bottomed out and not before, the mulch is applied over and around the plant.
Unlike in the warm months when we use only 2 to 3 inches of mulch, during the winter months we want to use six inches of mulch, or more. We want to keep the soil as cold as possible and the thick layer of mulch will act like a barrier between the soil and fluctuating ambient temperatures. The root systems of landscape plants are sensitive to ambient temperature changes and the mulch will prevent damage from premature spring growth.
Materials used for mulch during the winter months are different than those of summer. Straw, leaves and evergreen boughs make good layers as these are bulky without having excess weight that could cause damage to your plants while being covered. They are easily removed in the spring and then put into your compost pile.
Be sure to remove any stems or leaves that have fallen off during autumn before mulching as these could be a over-wintering home for diseases and insects.
Written by Dr. Gary R. Bachman, Assistant Extension Professor of Horticulture, Coastal Research & Extension Center.