How was farming possible in the thousands of years before the use of commercial fertilizers, herbicides and pesticides? You can look to your local forest floor for one possible answer. Beneath the layers of fallen leaves, twigs, wood chips, moss, and pine needles is usually a dark, rich soil, full of life which plants thrive in. The leaves and twigs on top of the soil eventually break down into soil themselves, which is then covered by more falling leaves and natural materials which feeds, and later turns into, soil, thereby creating a cycle of healthy mulching and soil creation. The healthy, vigorous plants grown in this soil often have natural defenses against disease and increased productivity without the use of additional fertilizers, herbicides or pesticides.

In order to imitate these conditions, a gardener just needs to add natural materials (mulch) on top of their soil and around their plants. Adding natural mulches has many benefits:

1.  It hinders weed growth by blocking the sun needed for seed germination. Likewise, weed seeds have difficulty growing in mulch, and those weeds that do inevitably grow are often easier to pull from the ground.
2. A mulch layer will help retain moisture in the ground. This helps your plants during droughts and results in less watering on your part.
3. Mulches help regulate the ground temperature more consistently in both summer and winter.
4. If you have a very heavy rainfall, the mulch (especially wood chips) will help soak up the excessive water.
5. As mulch breaks down, it provides nutrients to your plants and the soil which attracts and feeds other living things, thereby helping create an ecosystem.
6. It can help prevent soil compaction. In addition, using natural mulches is free and a good way to use a resource readily available that is often wasted (think of bagged leaves).
7.  One of the main reasons people use mulch is because it is extremely attractive in garden beds and landscapes.

Many gardeners add a 6-inch layer of wood chips in their garden beds every year to reap these benefits. If you have access to shredded green leaves and wood material combined, such as landscaping debris from an arborist or tree trimmer, this is a wonderful soil amendment. The green materials help the brown materials break down faster and provides nitrogen to the soil. If you contact a local arborist, they may be willing to drop off a load of wood chips at your home. While another resource arranges wood chip drops at your property, free of charge. However, please note that most companies will only give you a full dump truck of chips and cannot give half or quarter sized loads. This is a very large amount of wood chips, so be wary of the work entailed to move these off your driveway and into your beds. Adding fresh compost before you mulch is also beneficial. If you have heavy weed growth, you can place cardboard or newspaper on the ground first, then compost, then mulch.

Garden bed with mulch. Photo: Michael W. Thomas – Extension Master Gardener Volunteer

However, to be fair, there are some downsides to using mulches. Using wood chips can initially decrease the nutrient levels in your soil, as the wood chips act as sponges so to address this, just add fertilizer. Another downside to using pine straw as a mulch is that it does not break down quickly and can also increase the acidity of your soil when it does. To combat this, a proper application of lime, based on soil test recommendations, should be used. Finally, if using mulches like hay, straw, or grass clippings, be careful to make sure that water can still reach the soil and that matting does not occur. You should also be aware of the source of your mulch, especially if you are growing organically. Whatever has been sprayed or applied to the grass, shrub or tree clippings will inevitably break down in the soil where it is placed.

Overall, the benefits of mulching outweigh any negatives and what may result is a healthier garden and happier gardener.

If you would like more gardening tips, please contact North Carolina Cooperative Extension or call (252) 222-6352.

Written by Michael W. Thomas – Extension Master Gardener Volunteer – Carteret County