Mulching soil is one of the kindest ways that we can look after our gardens. Well-rotted compost or manure will help to bind light, sandy soils as well as increase the amount of moisture that can be held within them. Heavy, clay soils will be gradually broken up by the compost being taken down into the soil by worms, which then breaks down to leave air spaces for better gas exchange and channels for water to drain more effectively.
Soil erosion is a topic that gardeners are becoming increasingly aware of, as well as how detrimental it can be to lose our precious topsoil through erosion by wind. Adding a generous layer of mulch on top of your exposed soil during the early winter will protect it and give the added benefit of increasing biological activity within the soil structure. Don’t be intimidated by the thickness of your mulch – be generous with your covering as a liberal 10cm-thick layer across the surface either in autumn or late winter will benefit your garden no end.
The most important rule when it comes to mulching is to make sure that the soil is moist and weed-free. Perennial weeds such as bindweed and ground elder will thrive with that extra fertility, so it’s best to get them out first (or as much of them as you possibly can).
Mulching is wonderful for locking moisture into soil, but that moisture needs to be there in the first place. The danger of mulching on top of a dry soil is that it locks out the rainfall and the mulch becomes a barrier, which will have a negative effect upon plants.
By mulching each year, the growth in your plants will become apparent rapidly. I have been amazed by borders, especially those containing shrubs, that take on a new lease of life and grow in a far more vigorous and healthy fashion compared with when I didn’t add a layer of mulch.
One of the drawbacks of composting at home is that we struggle to achieve those warm temperatures in our composts, which can result in some interesting plants popping up here and there. I’m sure we’ve all had a rogue potato or onion pop up in unusual places as it’s gone through the compost and survived to see another year. Heat is the key: larger, well-turned compost heaps generate much higher temperatures due to the amount of decomposition that is taking place, which acts as a sterilant, killing off weed seeds and disease. At home, try to turn your compost to add oxygen, which will help to accelerate the rotting process, achieving higher temperatures. If you’re unable to do this, consider a local supplier of green waste compost, which is often a cheaper option and, as it has been created in large quantities, provides a sterile product with lots of fertility.