Mulch & Mulching 


A mulch is a layer of material applied to the surface of an area of soil. Mulching is generally used to improve the soil around plants, but it also gives your garden a neat, tidy appearance and can reduce the amount of time spent on tasks such as watering and weeding. Mulches help soil retain moisture in summer, prevent weeds from growing and protect the roots of plants in winter.


What is mulch?

Mulches are loose coverings (e.g. grass clippings, well rotted manure, wood bark chips, spent mushroom compost, straw [ideal for strawberries], spent hops [poisonous if eaten by dogs] or seaweed are a few examples of organic mulches). However you can use sheets of material placed on the surface of cultivated soil, often a porous membrane. Mulches can be applied to bare soil or to cover the surface of compost in containers.

Depending on the type of mulch used, there are many benefits of mulching including:

  • Help soils retain moisture in summer
  • Suppress weeds
  • Improve soil texture
  • Deter some pests
  • Protect plant roots from extreme temperatures
  • Encourage beneficial soil organisms
  • Provide a barrier for edible crops coming into contact with soil

The simplest of mulches, which is readily available and VERY effective is an application of short grass clippings. A method often adopted by vegetable gardeners is to cultivate a bed where the veg. is to be grown. Clear ALL weeds and then plant the seedlings (especially useful when growing beans and other legumes like peas). After planting, a grass clipping mulch is applied around the seedlings (taking care not to cover them & preferably try not to bring the mulch in contact with the stems - especially at an early stage of growth).


On the left is an example of a grass mulch used on my own vegetable plot for runner bean growing.


The mulch is particularly useful in this context as runner beans require constant moisture. With a mulch of this kind the soil surface does not dry, weeds are suppressed, the plant roots remain cool and in autumn, when the crops have been harvested, the mulch is dug back into the soil to fully rot - providing humus and nutrients for next year's plants.


The use of this kind of mulch also encourages earthworm activity. As we all know - the earthworm is THE No. 1 helper and friend of any gardener. They are the processing factories that transform everything compostable on the soil surface, dragging it down into the earth and nourishing the soil with their casts. One small downside - blackbirds love to eat worms and soon discover that by kicking and pecking your mulch to expose the soil they can get at the worms. Once they start this habit it's a constant job to rake the mulch back into place! However it's a small price to pay, as they also devour slugs, snails and other pests - so work around them and don't scare them away!


Some gardeners will point to the negative aspect of this type of mulch, saying that because it's moist and provides shelter it encourages snails. In my experience this is not a valid argument. The presence of slugs and snails is not more apparent when a mulch is properly used. Lack of weeding and the poor maintenance of grass around your crops coupled to the untidy scattering of debris (such as old containers and trays) around the plot is a far more troublesome source of slug and nail infestation.


A word of warning when using grass clippings from mowed lawns. NEVER use grass that has come from a lawn treated with herbicides such as the popular "Weed & Feed" poisons that have become popular with lazy lawn gardeners over the years. You can inadvertently be poisoning your crops as the herbicides wash off the mulch and on to your plants.


Here are a few more examples of mulching:


 Gwilym ab Ioan 2013