Mulch is the term used to simply describe the action of putting a covering layer on the ground/soil. There are many benefits for using mulch, using an ‘organic’ mulch brings many more benefits than using a ‘non-organic’ mulch such as plastic or gravel.
Why should I use compost/bark as mulch in my garden?
Using organic mulches, such as compost, in your garden can bring the following benefits:
- Suppress weed growth
A thick layer of mulch deprives weeds seeds of the light and bare soil that they need to germinate, preventing weeds from gaining a foothold underneath the mulch and from above by not being able to reach the soil.
- Retains moisture in soil
Mulching prevents the evaporation of moisture from the soil. Using compost as mulch also helps to reduce ‘run off’ after watering as the compost acts as a sponge, holding water and allowing the excess to filter through. Regulating moisture is important to help build strong healthy plants.
- Insulates plants from extreme weather conditions
A thick layer of mulch will help protect plants from the extremes of weather during the cold winter and warm summers. As with moisture regulation, temperature regulation will help to build strong plants.
- Feeds the soil as the mulch will break down, also improving the soil structure
Compost Mulch will break down over time to release nutrients, feeding the plants by adding more organic matter to the soil structure. Worms will come to the surface for the organic matter, taking it back into the soil, increasing aeration in the soil and leaving a trail of nutrients behind them. Not only will the soil structure be improved, but there will be less need to purchase artificial fertilisers.
- Increases microbial activity in the soil
Compost is an organically activity substance, and as the Compost Mulch breaks down, it takes microbial activity which improves the overall soil health and encourages root growth.
When should I mulch?
Autumn is the perfect time to mulch. The soil is still warm and the rain will have moistened the soil.
The mulch will help to regulate temperatures and moisture over the cold winter, and the soil structure will be improved going into spring.
In spring, when the ground starts to warm up again, remove the remainder of mulch ready for planting; before reapplying mulch to regulate moisture and temperature in the soil during the hot summers.
How to apply compost mulch?
The common mistake made when applying compost as mulch is that not enough is used! You need to apply a 5-6” layer to smother the weeds and regulate moisture and temperature.
Weed the area first (or the mulch might just feed the already established weeds!), water the soil area well, or apply after rainfall, apply the mulch and then water that well. Leave a gap around plant stems, or the mulch might cause damage to the plant: leave an inch or so diameter around the plants.