Coarser mulches such as pine bark nuggets and pine straw do not support the growth of weeds as much as the finer compost materials. Herbicides can be used for additional weed control. Advances have been made in this area and products are available that are safe for the plants and are non-toxic to our environment. Contact your county Extension agent for help in selecting the right herbicide for your planting needs. A commonly used mulch is black plastic.
Black plastic suppresses weeds, but it also limits water infiltration and gas exchange.
Roots under this material are usually concentrated at the surface where oxygen is available. Additional mulch is required for aesthetics. This mulch is usually washed away or decays to expose ugly, weathered black plastic. Black plastic is not a good choice for mulch. Fabric mulches are more effective than black plastic, but additional organic mulch is still required for aesthetics.