Mulching is one of the simplest and most beneficial practices you can use in your garden. Mulch is any material that is placed on top of the soil, not mixed with the soil. Mulches can either be organic such as grass clippings, straw, shredded leaves, bark chips, and similar materials; or inorganic such as stones, decomposed granite, and plastic. Inorganic mulches are generally used for permanent landscapes. Both organic and inorganic mulches can be beneficial to your soil and plants.
Why go to all the trouble of spreading mulch? Just 2 – 4 inches of mulch spread on top of the soil will:
• Protect the soil from erosion
• Prevent soil compaction that happens from the impact of raindrops in heavy rains
• Conserve moisture by reducing evaporation from the soil surface, reducing the need for frequent waterings
• Acts as an insulator, keeping plant roots warmer in winter and cooler in summer
• Reduce weed growth
• Keep fruits, vegetables and feet clean instead of muddy
• Enhance soil fertility
Organic mulches also improve the condition of the soil. As they slowly decompose, they provide organic matter which helps keep the soil loose. This improves root growth, increases the infiltration of water, and also improves the water-holding capacity of the soil. Organic matter is a source of plant nutrients and provides an ideal environment for earthworms and other beneficial soil organisms. Gravel or rock mulches also reduce water loss but don’t add fertility to the soil.
At the Oracle Community Learning Garden, we are working towards mulching all of the bare soil – not just the garden beds – using whatever organic materials are available. So far we’ve used straw, horse manure, finished compost, wood chips and shredded plant materials from neighbors’ yards. It just feels good to divert materials from the landfill while enriching and protecting soils and conserving water. And a lot of our recent monsoon rain is now stored in the soil instead of having run off the property.
While mulch is a pretty simple concept, there are a few mulching rules of thumb to think about.
Most organic mulch – straw, wood chips, and tree bark are examples – is carbon-rich. If mixed with the soil next to your plants instead of placing on top of the soil, it could reduce soil nitrogen due to more rapid decomposition. Nitrogen use is much slower if mulch is not mixed in with soil.
If your property is hilly, you’ll need to anchor the mulch so that it doesn’t wash away. This can be done by making basins or berms and covering them with mulch to slow the runoff. Don’t mulch up against the base of be plant – keep it a few inches out from the plant base or tree trunk to prevent rotting.
Why not start a Mulch Matters program and “plant the rain” to help build your soil, reduce erosion, and maintain soil moisture? Mulch is the key to keeping the rain that falls on your property in the soil, where it belongs.
Do you need help with your mulching plan? Send us an email at email@example.com or call Laurie at 910-670-5665.