Mulching - that is, protecting patches of bare soil with some kind of (usually) organic matter - is a wonderful conservation exercise, saving time, energy and water in the garden. Some mulching materials even feed the soil.
Before mulching, it is essential to weed and water the ground and remove any rogue slugs and snails. Grass cuttings, which so often end up in a slimy heap at the end of the garden, are an ideal material; use them in the vegetable patch or in out-of-the-way places if you don't like their appearance. Build up thin layers of about an inch or two at a time, greater depths can rot into an undesirable wet mass.
Other mulches include garden compost (but beware, because it can be full of weed seeds), straw, spent brewers' barley, chipped bark (use only around established shrubs and trees) and spent mushroom compost (which adds lime to the soil). Dubliners may like to try the composted green waste from the recycling depot at St Anne's Park, Raheny - it comes highly recommended by keen gardeners.