Mulch helps prevent weeds from springing up and helps plants retain moisture. It also helps provide a favorable environment for beneficial organisms to live. Finally, it protects the soil from compacting.
Consider some of the different substances below you can use to mulch your garden. As you can tell, we have tried and used most of these options. Mulch doesn't have to be expensive. Try to find something you can get for free in large quantities in your area or use a combination of the following materials.
Wood chips. We got a load of wood chips when we had a tree taken down and chipped up. This pile of wood chips has lasted us for years despite mulching every pathway for the past four years. Best applied to pathways instead of flower beds, wood chips are slow to decompose and keep weeds from springing up when freshly applied. This spring, I mulched a path with a new layer of wood chips and only made it halfway down the row. There have been no weeds on the new layer of wood chips while the old layer had weeds growing all over it. Wood chips used in combination with brown cardboard are a great combination for establishing new pathways.
Compost. As compost breaks down, it can be used as mulch. The longer your compost is left to decompose, the more nutrient dense it becomes and the more sparingly it should be used. For mulching purposes, compost that has begun to break down but still has large chunks in it can be spread on the top of flower beds to help maintain moisture and keep weeds from sprouting.
Pine needles. We have three huge pine trees in the middle of our field. They provide a great, free source of mulch with their needles. There is an assumption that pine needles lower the pH of the soil, making it more acidic. However, as pine needles decompose, their pH is neutralized. You would have to work the needles into the soil in order to impact the pH level of the soil. Pine needles take a long time to decompose and are light and fluffy.
Wood shavings. Last summer, a friend cut down trees around his house to make home repairs and was able to mill the wood. We used the sawdust and shavings from the milled wood as mulch (as seen in the beds above). The shavings worked well to suppress weed seeds, but also solidified into a crust on top of the bed. Looking back, I can see that the smaller particles of sawdust created a barrier that kept water from being absorbed. Jesse Frost mentions in his book The Living Soil Handbook that "wood chips steal nitrogen only in the immediate zone where they touch the soil...so [sawdust] is going to have a greater extent of contact with the soil and therefore utilize more nitrogen in the decomposition process." This means that, as the wood shavings break down, they will steal nitrogen from the plants they are around. Consider this before applying sawdust and shavings around your plants. If you want to get your own wood shavings, you can buy bags of pine shavings that are usually used as animal bedding. Stay away from cedar shavings.
Grass clippings. If you are able to collect your grass clippings during the summer from your mower, put them to good use as mulch around your plants. The nitrogen from the grass will naturally fertilize your plants as the grass breaks down. Make sure to cut your grass before it develops a seed head. Do not use your clippings as mulch if you applied any kind of herbicide or pesticide.
Weeds. As I pull weeds, I sometimes leave them to dry out in the pathway. With enough weeds, you can create a mulch around your plants or on your path. Just make sure to pull them before they go to seed.
Straw. Straw is a byproduct of a grain crop with the seed head removed. It has many uses around the farm and can be used for animal bedding or mulch. You can use it in the winter to insulate plants or put it down over cover crop seed to protect it from birds. Straw is light weight. Make sure to get straw that was grown without pesticides or herbicides.
Leaves. One of my favorite free mulches is leaves. Every year, we collect bags and bags of fallen leaves off of our property, many of which are chopped up through the lawn mower. These leaves make an excellent mulch and are a great way to suppress weed seeds. Chopped leaves are also a great addition to your compost pile.
What do you use for mulch on your farm or in your garden? What options are available in your area? Have fun mulching!