Mulch is a material applied to the soil to provide protection or aesthetic improvement to a selected area. Mulch material is either organic, such as bark, leaves, and straw, or non-organic, such as stones and black plastic.
There are many beneficial effects on the soil and plants due to mulch, some of which are:
- Prevents the evaporation of water from the soil, therefore, less watering is required.
- Prevents over-drying of the soil, which in turn allows absorption of water around plant roots.
- Insulates the soil; keeps it cool during the warm summer months and warm during the cold winter months.
- Reduces weed problems. If applied approximately 4 inches deep, the germination of weed seeds will be prevented. A thick layer of mulch will smother existing small weeds.
- Ads interest to the garden area.
- Prevents mud from splashing onto plants, which could otherwise cause plant loss due to soil-borne diseases.
Despite these benefits, there is a downside to mulch. Large weeds cannot be smothered, and if the mulch contains weed seeds, these seeds may germinate. Slug and rodent problems may increase.
“New” mulch is identified as tree limbs recently made into mulch. New mulch should be aged for a season before it is worked into the soil as the soil may become leached of nitrogen. New mulch can be used on top of the soil around plants as well as on walkways.
|Black plastic||–||Holds moisture and controls weeds. Cut holes for drainage.|
|Composted leaves||2-3 inches||Breaks down rapidly. Adds humus and food to soil.|
|Grass clippings||2 inches||Excellent mulch. Will break down rapidly in soil.|
|Gravel||2 inches||Holds moisture. Looks good with woody plants|
|Ground corncobs||2-3 inches||Improves fertility in soil. Good for roses and other plants that require medium acid soil.|
|Hay||3-4 inches||Reduces weeds and holds moisture well.|
|Peat||2 inches||Soak well before using as may scatter easily. Breaks down rapidly.|
|Pine needles||3 inches||Adds acid to soil.|
|Sawdust||2 inches||Use weathered sawdust if mixing with soil. Fresh sawdust may leach soil of nitrogen as it breaks down. OK to use for walkways. Breaks down slowly.|
|Wood chips||4 inches||Use weathered wood chips if mixing with soil. Fresh wood chips may leach soil of nitrogen. OK to use for walkways.|