You put mulch or decorative stones on top of soil.
Covering the surface of your soil with a layer of material like mulch or decorative stones is a common and beneficial practice. These materials serve a practical purpose beyond aesthetics, primarily helping to maintain optimal soil conditions for plant growth and overall garden health.
Why Cover the Soil?
As highlighted in the reference provided, covering the soil with a layer of mulch or decorative stones helps retain moisture in the soil. This is achieved because the covering acts as a barrier that reduces evaporation, ensuring that the soil remains consistently moist.
Beyond moisture retention, covering soil offers several other significant benefits:
- Weed Suppression: A layer of mulch or stones blocks sunlight from reaching the soil surface, inhibiting weed growth.
- Temperature Moderation: They insulate the soil, keeping it cooler in the summer and warmer in the winter, protecting plant roots from extreme temperature fluctuations.
- Soil Improvement: Organic mulches break down over time, adding nutrients and improving soil structure.
- Erosion Control: Covering helps prevent soil compaction and erosion caused by rain and wind.
- Aesthetics: Mulch and stones create a clean, finished look for garden beds and landscapes.
Types of Soil Coverings
There are two main categories of materials you can use to cover soil: organic and inorganic.
Organic Mulches
These are derived from natural materials and decompose over time, enriching the soil.
- Wood Chips/Bark: Long-lasting, good for paths and large beds.
- Shredded Hardwood: Knits together well, less likely to blow away, good for slopes.
- Straw: Often used in vegetable gardens, inexpensive.
- Compost: Adds significant nutrients, improves soil structure.
- Pine Needles: Good for acid-loving plants.
- Grass Clippings: Use thin layers to prevent matting.
Inorganic Coverings
These materials do not decompose and primarily offer moisture retention, weed suppression, temperature moderation, and aesthetic benefits.
- Decorative Stones/Gravel: Durable, come in various colors and sizes, good for Xeriscaping or around plants that prefer dry conditions.
- River Rock: Smooth, rounded stones, provides a natural look.
- Lava Rock: Lightweight, porous, retains some moisture.
- Plastic Sheeting/Landscape Fabric: Placed under mulch or stones to suppress weeds more effectively, but can impact soil health and drainage if not used properly.
Choosing the Right Covering
The best material depends on your specific needs:
| Purpose | Recommended Covering(s) | Notes |
|---|---|---|
| Moisture Retention | Organic Mulch, Stones | Reference confirms effectiveness. |
| Weed Control | Dense Organic Mulch, Stones | Deeper layers offer better suppression. |
| Soil Improvement | Organic Mulch (Compost, Bark) | Decomposes and adds nutrients. |
| Aesthetics | Decorative Stones, Dyed Mulch | Choose based on desired look. |
| Slope Erosion Control | Shredded Mulch, Heavier Stones | Materials that interlock or are heavy stay put. |
Applying a layer typically 2-4 inches deep for mulch is effective for most benefits. Stones may require a slightly deeper layer depending on size.
By applying a suitable covering, you protect your soil, conserve water, reduce maintenance, and enhance the beauty of your garden or landscape.
