Mulch is used for several things: to retain moisture in the soil, keep weeds at bay and keep the soil cool. They also help make the garden bed look more attractive.
There are many types of mulches available. Organic mulches help improve the soil’s fertility, as they decompose. Examples of organic mulches are: Bark, either chipped or shredded, grass clippings, shredded leaves, straw, compost or composted manure and newspaper.
Whilst organic mulch will decompose and have to be replaced, it does improve the fertility of the soil and its organic content. Mulch that is woodier and much drier will be slower to decompose which means the soil will get a lot less nutrients.
If you use manure, compost or straw it is advised you know the origin as these may have weed seeds, which will mean your mulch could start sprouting after spreading if not careful.
The best uses for bark mulches are around trees, shrubs and garden beds. Especially where there won’t be much digging such as walkways or foundation plantings. Woody mulches like bark do not mix very well into the soil so if you have to keep moving them to make way for new plants it can become a nuisance.
As mentioned earlier, providing they are virtually weed free compost and composted manure can be used anywhere. Use as either a coating of mulch, or side dress your plants in the growing season as this will insulate them and also give a boost of some slow released nutrients to the soil.
Like most green plant debris grass clippings have high water content and decompose very quickly. They are best used in the parts of the garden where you want to suppress weeds. If you have a mulching mower leave the clippings on the lawn as this will add fertility to the soil. If you have bagged the grass clippings be sure not to throw away unless a weedkiller or other pesticide has been used on your lawn. Untreated grass clippings can be used to mulch unplanted open areas or put into your compost bin.
For years shredded newspaper has been used to keep the roots of plants moist in shipping. Layering newspaper sheets has great moisture retention abilities. They also act like other organic mulches when it comes to controlling the temperature of the soil and suppressing any weeds.
Not all gardeners like using shredded leaves as mulch, especially those with formal gardens. But they can be used as mulch anywhere. If you spread a layer in the spring, before plants spread out, the leaf mulch tends to blend into the view within a short time. And spreading over vegetable gardens in autumn means they will begin to decompose over the winter.