When we face challenges in our garden such as hot and dry weather it is always a good idea to step back and have look at how nature handles these problems. Leaves collect on the forest floor and form a protective blanket that conserves water and breaks down to enrich the soil. When walking through a grassland you will notice that the soil is covered in old plant material and grass which forms this same protective layer. This is mulching in its simplest form.
Mulch is any material that covers the bare soil and thereby forming a protective layer on top. The added benefit of using an organic mulch is that as it breaks down it enriches the soil. Living mulches are plants that cover the ground and has the same effect as other mulches by conserving water. A living mulch allows you to add colour and texture at ground level. Where possible try to use indigenous ground covers. Some of the benefits of mulch are:
- Suppresses weeds by preventing germination.
- Conserves water by reducing evaporation by up to 70%.
- Feeds plants, earthworms, microbes and other beneficial life.
- Keeps the soil cool and moist in summer, reducing the need to water.
- Prevents erosion, compaction and crusting of the soil.
- Lowers soil temperature around the roots, which encourages plant growth.
- Mulched soils do not need tilling as the microorganisms do all the work.
- Organic mulches add to the nutrient base of the soil.
Different types of mulches:
Organic mulches
- Leaf mulch
- Compost
- Bark and wood chips
- Rooibos mulch
- Dried grass cuttings
- Pine needles
- Nutshells and peach pips
- Shredded newspaper
Inorganic mulches
- Gravel
- Plastic sheeting
- Pebbles
- Stones
- River sand
Living mulches
- Vygies
- Bacopa
- Verbena
- Gazania
- Plectranthus
- Mondo grass
- Hen and chicken
- Asparagus fern
How to apply mulch
Lightly rake the area that you want to cover with mulch to ensure that it is even and level. The thickness at which you apply your mulch depends on the density of the mulch. With a dense mulch such as compost or dried grass clippings, a 2-5cm layer is more than enough. Whereas a mulch like bark chips needs to be applied more thickly. As organic mulches break down they need to be replenished. Compost, for instance, breaks down faster than bark chips. Remember to mulch your pots and containers as they dry out faster than the garden beds. Always leave a small gap (2-3cm) around the trunk and stems of the plant to prevent possible stem rot.
Bear in mind that certain microbes that aid in breaking down organic material use nitrogen to aid the process. Thus, supplement with a slow release fertilizer to replace the nitrogen used up by the microbes. Pine needles increase the acidity of the soil which makes it perfect for use with acid-loving plants. Dried grass clippings should be applied in a thin layer to ensure that it decomposes instead of rots.
Mulching is the one practice in the garden that will save you the most time and money when used effectively. The best of all, your garden will provide you with all the mulch you need. Using mulch effectively will allow you to spend less time on watering and weeding. Let nature do the work and you will have a happier, healthier garden with more time for you to enjoy it.