by Lyn Gannon, Master Gardener
Tired of pulling weeds? Wincing about rising water costs? Want to enrich the fertility of your soil? Then consider using mulch in your garden! Mulch, especially when plant-based, offers innumerable advantages to home gardeners including:
- Reducing maintenance
- Minimizing water usage
- Equalizing temperature
- Improving soil quality and fertility
Maybe you're thinking: Hauling all that stuff is so much work! Is it really worth it? Yes! Mulch is one of most versatile tools available to gardeners. Specifically, mulch:
Controls Weeds
Mulch can reduce the many hours spent weeding your garden. Weeds rule the plant kingdom for 3 reasons: 1) Weed seeds germinate easily when exposed to light. 2) Garden soil is teeming with weed seeds; and 3) Weeds have adapted to survive under difficult conditions.
As a result, every time the soil is disturbed - even with the best intent - the germinating cycle begins again. Before long, your plants will be competing with weeds for water, sunlight and nutrients. And weeds are going to be the likely winners.
How to deal with those nasty weeds? Stop them from germinating in the first place! By blocking sunlight, you can stop them in their tracks, and give your plants a head start. Without a doubt, mulch is the most effective way to do this.
Later, once your bed is mulched, you'll still have occasional weeds from airborne seeds. But the weeds will easily be removed, because their roots are less entrenched. If the mulch is damp, weeds will come out easily with the twist of a trowel or when pulled by hand.
Conserves moisture 
Mulch acts as a porous membrane which easily absorbs water, while simultaneously reducing evaporation from the soil. During daylight hours, plants are constantly using water. Absorbing it through their roots, they use it to process nutrients, and eventually evaporate it through their leaves.
Want to enjoy your garden while still practicing water conservation? Mulch it! Both your plants and environment will benefit. Most plants can survive when moisture levels in the ground fluctuate, but they thrive when water levels are more even. Unfortunately, weather conditions vary. Hot and windy conditions are particularly challenging because they increase plant evaporation.
Bare soil loses moisture quickly. By adding mulch, you'll have a buffer which keeps the water where you want it - in the soil. In the process, you'll have healthy plants and minimize your water usage.
Moderates soil temperature
Like people, plants become stressed during extreme temperatures. Delicate plant tissue is easily damaged when exposed to intense heat and cold. During the summer, the sun can burn delicate roots hairs which lie close to the ground's surface. Even trees are not immune - 90% of their roots lie in the top 3' feet of soil. In the winter, the crown (base) of a plant can be easily damaged by frost. And, the longer temperatures are extreme, the more damage they cause.
Even during ordinary weather conditions, mulch can be a boon to your garden. The wear and tear of ordinary seasonal temperatures still affects the health of your plants. The key is to protect the crown and root, which form the core of most plants; the less they are stressed, the healthier your plants will be.
By acting as an insulating layer, mulch will minimize temperature fluctuations in the soil temperatures. Maintaining moderate soil temperatures, allows your plants to use their resources for growth rather than repair.
Enhances water absorption/prevents erosion
Bare ground is particularly vulnerable to the whims of nature. Wind can cause loss of valuable topsoil. Rain can cause erosion and add silt to waterways downstream. Heat and drought can kill valuable soil microbes. Severe frosts can kill plant tissue. A layer of mulch can't solve all the world's problems, but it can lessen the damage caused by all the above.
Unprotected soil sheds water easily. A thin layer of garden clippings on the same piece of ground will soften rainfall and help the ground absorb water. Branches stuffed into cracked earth can lessen erosion. Think twice about tossing ordinary garden cuttings and twigs in the re-cycle bin. They can contribute to the overall health of your garden soil by protecting it from the elements.
Enriches soil
Plant-based mulches have an added advantage over rock based mixes, because plant-based mulches can improve the fertility of your soil, which is the key to healthy plants.
Soil is made up of soil particles, air and water. Half the volume of ideal soil is pore space - the area between the particles, where air and water can penetrate. Because roots need air and water, pore space is essential to healthy soil. No amount of fertilizer will solve the problems created by dense, compacted soil. Organic matter promotes a crumb-like granular soil with better pore structure, improving your soil's water holding capacity, water infiltration, and aeration. Plant-based mulch will decompose and add organic matter to your soil, while feeding both the visible and invisible organisms that keep your garden healthy: earthworms and microorganisms.
Earthworms enhance your garden's aeration, drainage and nutrition by ingesting, grinding, and digesting large quantities of soil. Their castings (excretions) are richer in nutrients than the surrounding soil. By adding mulch to your garden, you'll develop a healthy workforce. Provide worms with what they need, and let them do the work!
Microorganisms are an essential link between the nutrients in your soil and plant growth. They insure your plant's health and development through sophisticated and symbiotic relationships with plants roots. And, like earthworms, they thrive in organic matter. They perform crucial tasks such as decomposing plant residues into the simpler forms needed by your plants. They also synthesize plant hormones, add nitrogen to the soil, and make soil minerals accessible to your plants. Your plants need these critters! By placing organic matter (mulch) on your soil, you create a virtual feast for microorganisms, which will increase the fertility of your soil.