Digging the Dirt on Mulch
What is Mulch? Mulch is any material placed on the soil surface to conserve moisture, lower soil temperatures around plant roots, prevent erosion and reduce weed growth. Mulches can be derived from either organic or inorganic materials. Organic mulches have a number of significant advantages over inorganic mulches, so where possible use them in preference.
Why is mulch important?
It looks good:
- Neat uniform finish
- Stops soil splashing up on plants and walkways when it rains
It’s good for the plants:
- Saves water by providing extra storage and by reducing the rate of evaporation from the soil
- Holds nutrients
- Stops weeds
- Gives plants an earlier start by insulating them from low temperatures
It’s good for the soil:
- Protects soil from being washed away, especially in sloping gardens
- Builds and protects the soil’s crumb-like structure which allows water to soak in better
- Builds up “young” soil by encouraging beneficial soil life such as earth worms and microbes
It’s good for you:
- Saves time weeding and watering
- Saves money spent on re-planting, water, fertilizer and pesticide
Where to get mulch:
Mulches can be purchased by the bag at home improvement stores and garden centers, but this tends to be an expensive option. The green waste recycling site, El Corazon in Oceanside offers a range of different types of mulches by the bag or by the truckload at very reasonable rates.
How to apply it:
The general rule of thumb is the finer and smaller the particle size, the thinner the layer of mulch needs to be. Also avoid direct contact with the base of plant stems, especially those of tender herbaceous plants.
| Mulch Materials | Thickness | Where to use |
|---|---|---|
| Shredded branches from tree trimmings; large two-inch bark | 4″ | Trees and shrubs |
| Leaves or leaves mixed with some grass clippings; one-inch size bark | 2″ | Shrubs and general cover |
| One-half inch and smaller materials; fine-screened and double-ground barks | 1″ | Small flowers and vegetables |



