What is mulch? Mulch is a protective layer spread over the ground to protect soil and plant roots from undesirable conditions.
The following organic materials can be used as mulch:
– hay (however this one you have to make sure the grass was cut before the formation of grass seeds)
– sawdust is a by-product or waste product of woodworking operations such as sawing, milling, planing, routing, drilling and sanding.
– peat moss – not only as mulch but a very popular soil amendment as well, helps sandy soil hold moisture, and clay soil loosen up and drain better. It has a naturally low pH of about 4.0, this makes it an excellent soil amendment for acid-loving plants or highly alkaline areas.
– grass/lawn clippings – from places where no herbicide has been used
– shredded bark, ground corn cobs, peanut shells, rice hulls, sugar cane waste, sunflower hulls, cottonseeds hulls, cocoa bean shells, pine needles.
Some of non-organic mulches include:
– plastic (polyethylene) – opaque black – the most successful non-organic material – prevents sunlight from reaching weeds (clear is not recommended since clear polyethylene allows weed growth under it)
– both clear and black polyethylene help preserve the moisture of the soil;
– landscape fabric – this one lets the water through, gets weeds suppressed; however, some weeds may get through the fabric anyway.
– Infrared transmitting plastic mulch – they allow infra-red light penetration, blue-green or brown in color.
What are the advantages of MULCHES/mulching:
One of the most important reasons for mulching is weed control. Mulch helps with water conservation as it slows down evaporation and that helps with reduced labor with suppressing weeds and plant watering.
Mulching keep soil temperature steady – as a general rule organic mulches tend to keep soil cool; clear and black plastic mulches may be used to warm the soil. It also helps reducing insect numbers – reflective plastic mulches (white, aluminium coated) have been reported to keep some insects off; cedar chips are believed to repel insects.
In addition, most organic mulch help reducing leaching of nutrients and water run-off. Many mulches such as woodchips, shredded bark or crushed rock create a nice and neat appearance of your garden and may help to keep the edible portion of vegetable crops clean, especially fruiting vegetables.
The Biology of Horticulture, An Introductory Textbook, John E. Preece, Paul E. Read
Eat Your Greens, The Surprising Power of Home Grown Leaf Crops, David Kennedy