Home gardeners have several types of organic mulch available that they can buy for use in the garden and the flowerbed. This article will list the common types of organic mulches and assess their pros and cons. Based on the situation that the mulch is needed for, the home gardener can then determine which type of organic mulch will work best.
Leaves: Leaves are the most readily available organic mulch, and they are free. In addition to cost, leaves provide a good winter insulation as well as plant nutrients. However, leaves spread too thick often pack together. Leaves will dry and blow around, however if they are chopped, that will alleviate the problem. Chopped leaves can be used into the spring or mixed into the soil once they are decomposing.
Pine needles: Pine needles are available and free provided there are pine trees nearby. Pine needles are acidic, which is good for plants that love acid, such as blueberries and strawberries. They don’t blow around as much, if at all. However, their rate of decomposition is slow, so they are not a reliable source of immediate nutrients. Adding fertilizer, preferably organic matter, will solve this.
Grass clippings: Grass clippings are free and contain nutrients. They decompose quickly but enrich the soil, but are easy to replace. However, they can bring in weed seeds, and tend to mat and will need to be fluffed up. Mixing grass clippings with another type of mulch such as shredded leaves will mitigate matting. Grass clippings from lawns treated with chemicals should not be used as the chemicals could affect the plants adversely. They should never be used for the vegetable garden if from a treated lawn.
Wood chips: Wood chips encompasses most mulches sold in garden centers, but also includes straight wood chips. Mulch is decorative and is good at preventing weeds from growing. Wood chips straight from chopped trees are cheaper, but often contain larger fragments of wood and are not as decorative. Decomposing wood uses nitrogen in its decomposing process, and this sometimes creates a nitrogen deficiency in the soil. When buying wood mulch, check for quality. A forest blend mulch or colored general wood mulch is often made from junk wood or pallets and can be inferior in quality. Many mulches, especially red or black ones, are dyed that color.
Bark mulches: Bark mulch controls weeds well and is easy to find places that sell it. However, it can be more prone to going sour in wet years. If the mulch begins to smell sour, it is spread too thick and the lack of oxygen is causing the smell, from creating an acid that is toxic to plants. To remedy sour mulch, allow it to air out. Remove excess mulch and fluff up the remaining mulch, or simply remove all the mulch and air it out after soaking it. When the mulch ceases to smell, it is safe to spread, but take care not to spread it too thick.
Sawdust: Sawdust is inexpensive to buy and slow to decompose. However, it uses nitrogen in the soil to decompose, and often mats together and inhibits water from penetrating through to the soil. It is recommended to let the sawdust age for a few months outdoors in the weather before using.
Buckwheat hulls, cocoa shells, and similar mulches: These mulches are recommended for flowers and vegetable gardens, but are prone to blowing away in open, windy areas. These mulches are often expensive to obtain. It must be kept wet to stay in place until it ages, and cocoa shells sometimes also mold.
Hay, salt marsh hay: Hay mulches, often used when reseeding lawns, are useful during the entire year. They provide winter insulation and inhibit weeds and retain moisture in the soil in summer. Hay mulches are good for vegetable gardens, to keep the fruits of watermelons and squash off the ground and prevent rot. These mulches are more flammable than wood mulches and can blow away in exposed or windy locations. Hay can contain weed seeds, salt marsh hay is weed-free as the seeds in salt marsh hay are not adaptable readily to garden conditions.
These are some of the most common items used for organic mulches. Inorganic mulches, such as stone, plastic, and fabric are also used, and they have their pros and cons also. Stone is low maintenance but permanent, making it hard to amend the soil; plastic is used on farms and in vegetable gardens but requires irrigation as it repels water, and landscape fabrics control weeds well but over time, weeds grow in organic matter that accumulates between the fabric and the mulch above it.
So by weighing the pros and cons of the different mulches, the gardener can decide which mulch is best for their landscape, flowerbeds, vegetable gardens, flower gardens, and yards.
