Another week goes by, and for most of us, no significant rain. Prolonged drought can take a toll on our lawns, gardens and landscapes.
For the last several weeks, we’ve been looking at practices and steps we can take to help our gardens and landscapes deal with the drought and conserve water. These steps include: 1) planning your landscape with water conservation in mind; 2) using plants adapted for our area and your soil type; 3) having practical turf areas; 4) improving the soil prior to planting; 5) employing efficient irrigation practices; 6) using mulches to cover bare soil; and 7) applying appropriate maintenance practices.
Mulching is one of those practices that should be used in every garden and landscape. Mulches serve several purposes, and greatly aid in the health of a landscape.
So, just what is mulch? It’s simply a protective ground covering that saves water, reduces evaporation, moderates soil temperature, prevents erosion, controls weeds, and in the case of organic mulches, enriches the soil. Almost sounds too good to be true, which is why the Smith County Master Gardeners have a little brochure called ‘Miracle Mulch’!
Mulches are classified as organic or inorganic. The organic mulches are more popular and include leaves, bark, pine needles, compost, wood chips, straw and similar materials. Inorganic mulches include rocks, rock chips, synthetic fabrics, and other non-plant materials.
A major benefit of mulching is it greatly reduces soil moisture loss through evaporation. Both plants and our water bill are helped by reducing the need to water plants so frequently by applying mulch around flowers, shrubs, young trees and in the vegetable garden.
Remember how windy it has been the past couple of months? Mulches also reduce the soil’s exposure to wind which, in turn, reduces water loss through evaporation.
The insulating quality of mulch helps keep the soil cooler in the summer and warmer in the winter. By maintaining more even soil moisture and temperature, mulch promotes better root growth and plant health.
Erosion control also is important, especially on slopes. Mulch helps to reduce rain splash and runoff, which in some cases also help prevent the spread of plant disease.
Mulch suppresses the growth of many weeds. A 2- to 3-inch layer of organic mulch should be sufficient to prevent sunlight from reaching the soil, thereby reducing the chance of weed growth. Any weed seedlings that do manage to germinate and break through the layer of mulch are easily pulled. A mix of coarse and fine mulch particles helps reduce seed germination.
Another benefit of organic mulches is that they enrich the soil as they decay, forming a rich, dark organic material called humus that provides nutrients for the soil and improves its texture, which in turn enhances root growth. Because organic mulches break down over time, they need to periodically be replenished, thus providing a source of some of the needed plant nutrients as they continue the process of decomposition.
Last, but not least, mulch has aesthetic value. There is a range of colors and textures. When added to the garden floor, the uniform quality of most mulches serves much the same aesthetic purpose as a carpet in a home, serving to visually tie together the various plants and sections of a landscape scene.
It’s a good idea to check the garden a couple times during the year and renew areas where the mulch has gotten thin. There is no need to remove the old and replace with new mulch, since soil organisms will work the decomposing organic matter into the soil, increasing the health of the soil.
Just don’t pile it on too deep! One of the biggest mistakes folks make when applying mulch is to create little (or big) volcanoes of mulch piled up against the trunk and around the base of newly planted and young trees. If the mulch stays wet, this can cause decay problems on the bark of the trunk. And, if the mulch is too deep, the roots can be starved for oxygen, and/or grow up into the mulch. The International Society of Arboriculture recommends a mulching depth of 2 to 4 inches, pulled away from the trunk of the tree (kind of like a donut) to expose the natural “flare” of the roots.