Some organic materials available in your own yard can be regarded as sources of free mulch. The two best examples (more will be discussed below) are grass clippings and the leaves you rake up in fall. For optimal use as mulch, however, each should be “prepared” ahead of time. For those as much in need of saving time as saving money, black plastic and poly tarps are good quick-fix mulches. You can cover a lot of ground with them quickly, and, if you shop around, they are relatively cheap.

Bark Mulch

When you have large areas of the landscape to cover with mulch, mulching can get expensive and labor-intensive. Colored bark mulches (red, black, etc.) are attractive and very popular, but they are suitable only for covering small spaces if you are landscaping on a budget. What is the solution? Consider alternatives to conventional mulches, including not only cheap mulches but even some free mulches. The following ideas will be inappropriate in some situations but a lifesaver in others.

Labor-Saving Cheap Mulches

Black plastic is a widely used landscape mulch in the nursery business. While not attractive, it is at least neutral in color and might not be unacceptable in a backyard. It is cheaper and easier to cover a large area with black plastic mulch than with the more expensive bark mulches. Like black plastic mulch, poly tarps provide a cheaper and easier alternative to bark mulches for covering large areas. One advantage poly tarps have over black plastic mulch is that they are sturdier. However, the color of poly tarps (commonly blue) is often more obtrusive. But, in a pinch, use poly tarps as a temporary mulch. Then go back afterward and cover them with something more attractive (perhaps one of the free mulches discussed below). If you are intent on finding a free mulch that can function like a tarp, then keep an eye out on trash day for old carpeting that people are throwing out.​

Free Mulches

LeavesGrass clippingsStonesPine needlesCrushed seashellsNewspaper

Perhaps the best example of free mulch is the leaves you rake in fall. Another good source of free mulch is the grass clippings that are left over after you mow the lawn. But both of these free mulches should be “prepared” prior to use:

Leaves should be shredded first.Grass clippings should be allowed to “cool off.”

Not only will leaves look better as a mulch if shredded first, but they will also function better. Matted leaves form a barrier that prevents air and moisture from getting to the soil below, which is not a desirable quality in a mulch. If you do not own a wood chipper-shredder, simply spread the leaves out and run the lawn mower over them to shred them (preferably with the bag attachment in place on your mower, so that the leaves are all collected in one place, making it easier to transport them). Fresh grass clippings are too hot to be used as mulch and may burn your plants. That heat is great if you wish to use them to make compost, but you will want to let them cool off if you plan to use them as a mulch around your perennial or annual flowers. Fresh, grass clippings contain a lot of moisture. Do you want proof? If you rake them into a big pile, you can sometimes actually see steam rising from them. To prepare them for use as a mulch, simply spread them out first to dry. As they dry, their initially hot, steamy quality will dissipate, making them safe to apply around plants. If you have lots of small stones lying around on your property or have access to such a resource elsewhere, you can treat them as free mulch. Just be aware of a few drawbacks in using stone mulch:

It is difficult to keep clean and free of weeds. Leaves and other debris will fall between the stone where they are tough to remove. Whatever you fail to remove will break down over time, becoming dirt. Seeds will drop into this dirt and sprout, including weed seeds. Stones heat up when exposed to the sun. Some plants do not like having mulch around them that is hot. If you ever decide that you would like to get rid of the stones and try a different kind of mulch, then good luck. Small stones work their way down into the soil. It will take you forever to remove them.

Some gardeners may worry that using mulch with pine needles makes the soil too acidic for plants that do not like a low soil pH. For years, this was accepted as gospel. The jury is still out, but just be aware that some experts now dispute this idea and say that it is fine to use pine needles. If you happen to live near the ocean, crushed seashells present themselves as an obvious possibility for free mulch. But, like an area mulched with small stones, a flower border mulched with seashells will be difficult to keep clean and weed-free, plus it would be hard to get rid of the seashells later should you change your mind about them. Newspaper is often used in a very specific way as a mulch: namely, it is laid down (overlapping the sheets) on top of unwanted grass to kill it. In garden areas, “living mulches” are another option worth considering in this context since they are fairly cheap since you are just paying for the seed.