Organic mulches can keep weeds at bay while slowly releasing nutrients to your other garden plants. Chunky mulches are best for shading the soil; examples include bark chips that are slow to decompose, leaves that are quick to decompose and grass clippings that provide lots of nitrogen to green plants and lawns. read more
The best mulch to prevent weeds is also the cheapest. Free materials that also benefit soil include compost, leaves, sawdust or wood chips, straw or grass clippings. Search online classifieds or get to know local farmers, offering to buy hay bales that have gotten wet. read more
To use mulch as a natural weed barrier, you need to put down a 2- to 3-inch layer. That's enough to keep most weed seeds from sprouting. Because you block their access to sunlight, they won't have enough energy to push through the mulch. read more