The benefits of mulch are bountiful. Mulch limits weed growth, decreasing the maintenance needs of your landscape. Organic mulches decompose over time, adding nutrients and valuable organic material to the soil. And all mulches help to conserve water, keeping your plants hydrated while costing you less in water bills. Different mulch materials have different characteristics that make them better in specific landscaping situations.
Standard compost is usually the best mulch for home gardens, according to Virginia Tech University. Such material can be prepared at home, is typically weed-free--the heat of the compost pile kills most weed seeds--and is rich in the organic material that feeds the soil and can help boost vegetable growth.
Chopped-up pine bark is one of the best organic mulches when it comes to coarse mulching material, according to the North Carolina State University. It is common outside of vegetable gardens, such as around trees or in flower beds. The university likes pine bark because it lasts a long time--once applied, gardeners only have to replace it every few years--and conditions the soil. For the most attractive and longest-lasting mulch, use wood chunks that are 1 1/2 to 3 inches in diameter, according to the University of Florida. Bigger chunks are also better at keeping weeds at bay than finely chipped wood pieces.
Sawdust is the best mulch when a gardener needs to acidify the soil's pH levels. Virginia Tech recommends it for plants such as rhododendrons. Sawdust also says it works well for mulching pathways. Because sawdust isn't effective at stopping weeds, it is usually not advised for other landscaping situations.
Rocks like crushed gravel are ideal as a permanent mulch in landscaping areas like driveways and Japanese-style rock gardens. The University of Florida likes rock-based mulch because it comes in various colors, making it easy to match with your home's palette, and is also fireproof. Gardeners should note that light-colored gravel and rocks will reflect the sun's rays up onto the underside of plants, and sensitive plants may be scorched.