Mulch refers to a protective layer of material, such as bark, straw, or compost, spread over the soil surface around plants. Often overlooked, mulch is a gardener’s best friend, offering a multitude of benefits that go beyond mere aesthetics. It serves various purposes, including moisture retention, weed suppression, soil insulation, and enhancement of soil fertility. Mulch plays a pivotal role in the success of a thriving garden.

Moisture Retention: By forming a protective layer over the soil, mulch reduces water evaporation, helping plants retain moisture. This is particularly crucial during hot summer months or in arid regions, where water conservation is paramount.

Soil Fertility: Going hand in hand with moisture retention, mulch aids in soil fertility by preventing the top layers of the soil from drying out, which can occur quickly if the soil is left exposed on a warm day. When soil loses its moisture, the microorganisms living in it die, leading to less fertile soil. In addition to protecting existing fertility, organic mulches increase soil fertility as they decompose over time feeding microorganisms and adding nutrients for plant use in the soil.

Disease Prevention: Some soil-borne pathogens can cause foliage disease when water splashes back up from the soil. This is why it’s often recommended to water close to the base of a plant. Mulch provides a barrier between plant foliage and the soil limiting if not wholly preventing the transfer of these pathogens.

Weed Suppression: Mulch acts as a natural weed suppressant, preventing sunlight from reaching weed seeds and inhibiting their growth. Weeds can be superior miners of nutrients, robbing our plants of the nourishment they need. Mulching saves time and soil resources. 

Temperature Regulation: Mulch also acts as an insulator, regulating soil temperature by keeping it cooler in hot weather and warmer in colder seasons. This creates a more stable environment for plants aiding their growth and development.

Erosion Prevention: Mulch can help safeguard soil from erosion caused by wind and rain. This is particularly beneficial on sloped terrain, where erosion can be a significant concern, such as garden beds or hills without borders. 

Organic Mulch: Organic mulches decompose over time and provide the most benefit for soils contributing to moisture retention, soil fertility, disease prevention, weed suppression, temperature regulation, and erosion prevention. A plethora of options exist for organic mulches including wood chips, straw, compost or manure, cover crops or grass that has been cut, and wool.

Inorganic Mulch: Inorganic mulches don’t decompose like organic mulches, but they can provide a weed barrier and help to retain soil moisture. Rocks or gravel are the most common inorganic mulches. 

Living Mulch: Groundcovers and low-growing plants can serve as living mulch. These green companions protect the soil, reduce erosion, and add a dynamic, ever-changing element to the garden. Examples include creeping thyme or clover.

Apply mulch after planting or over bare soil in the Fall if you don’t plan to have crops growing through the Winter. Mulch is typically applied at a 2-4” thickness to ensure effective weed suppression and moisture retention. Ensure mulch is not applied at the base of plants to avoid moisture-related diseases. As the mulch decomposes over time, add more mulch where needed.

For Fall-planted crops, like garlic, or perennial plants that go dormant through winter, like strawberries, add 6”+ of mulch after planting or dormancy. Be sure to remove some of the mulch once the weather starts to warm so that the plants can easily sprout through the mulch.

Mulch is an invaluable resource in the garden, and no garden should ever be without it.