What Is Mulch?

Mulch is material placed over the soil surface to maintain moisture and improve soil conditions. Mulching is one of the most beneficial things you can do for the health of your plants. Mulch can conserve water loss from the soil, provide nutrients to soil and plants, minimize weed competition, insulate soil, control erosion and improve soil structure. Properly applied, mulch can give landscapes a handsome, well-groomed appearance. The Mulch Center’s manufactured products are 100% organic made from local tree debris, not from C & D waste (construction debris) or pallets.

Where to Apply Mulch

Mulch entire beds of trees, shrubs, annuals, perennials and/or ground covers. Mulching is an important practice for establishing new plantings. Mulch can be used instead of grass around trees and shrubs. This greatly reduces the competition for water and nutrients from the turf and increases the growth rate and health of your plantings. In addition to being useful around plants, mulch can be used as a ground cover for walks, trails and play areas.

How to Apply Mulch

Organic mulch verses inorganic mulch works best for your landscapes. Some plants may benefit from use of slightly acidifying mulch such as pine fines. Contact us should you have any questions on the type of mulch you should use - (847) 459-7200.

1. Prepare The Area

For optimal results, all areas to be mulched should be cleared of any existing weeds or grass before mulch is applied. You may want to install a weed barrier (landscape fabric) to help prevent new growth of weeds or grass, but is not necessary. Landscape fabric can be an additional precautionary step in weed control. A shovel and wheel barrow is helpful when transporting the mulch to your planting areas. A pitchfork and/or leaf rake should be used to spread the mulch evenly around your plants.

2. Spread The Mulch

MULCH AROUND TREES: According to the International Society of Arboriculture, the mulched area should cover as much of the tree root zone as possible, from near the trunk to the drip line is considered ideal. For recent transplants, mulch beyond the root ball. Maintain mulch for at least three years to facilitate root growth and to protect trees from mechanical damage. Where possible incorporate multiple trees and shrubs into one larger mulch bed, is more effective than single rings around individual trees. For larger existing trees, the minimum radius for mulch is at least three times the trunk diameter.

MULCH AROUND SHRUBS & FLOWERS: As with trees, mulch volcanoes are not recommended for your shrubs and flowers. It is recommended that you leave 1 to 2 inches of breathing room around the stem or base of the plant. Applying a deep layer of mulch exceeding 4 inches can cause unnecessary stress on your plants.

AVOID VOLCANO MULCHING: Unfortunately, North American landscapes are falling victim to a plague of over-mulching. A term, “mulch volcanoes,” has emerged to describe mulch that has been piled up around the base of trees. Mulch volcanoes cause the outer layer of bark on the tree to rot and leave your trees vulnerable to disease. See illustration for proper and improper mulching. Applying a deep layer of mulch exceed 4 inches can cause unnecessary stress on your plants.

3. How Many Cubic Yards of Mulch Will You Need?

Measure the square footage on the ground that you plan to cover with mulch (multiply length by width). Divide the square footage by 324 and multiply by the desired depth. Try our mulch calculator for further assistance. The recommended depth for existing mulch areas is 1-2 inches. The recommended mulching depth for new mulch areas is 3-4 inches. It is not recommended to exceed a total of 4 inches when mulching new or existing areas.

4. Maintaining Mulch

Remember, your mulch is an organic product and will weather from exposure to rain and sun. In addition, mulch decomposition rates may vary on the type of mulch that is being used, but can be refreshed during the growing season. Simply cultivate the top layer of mulch and you will have a fresh look. To keep your property well-groomed and plants healthy, annual mulching is recommended.

Although mulch helps to suppress weeds from growing, a force to be reckoned with is wind borne seeds. Wind-borne seeds can germinate on top of mulched areas and unwanted small weeds may appear. A garden hoe or cultivator will make it easier to get rid of small weeds with little effort by lightly stirring the mulch and uprooting the weed. Be sure to address the tiny weed problem before it becomes a giant weed problem.

Slime Molds

Slime mold is a brightly colored organism that spreads across wood mulches during periods when temperatures are warm and humidity is high. Most people report seeing patched or covered areas in mulched beds that appear spongy and sometimes cauliflower like. Although this can be disturbing to most gardeners, it’s no cause for alarm. Slime molds in the genus Fuligo are organisms that can appear bright yellow to orange, fading to brown and tan as they dry. They pose no threat to plants, animals or children.

You won’t find any miracle cures for slime molds because chemicals do not kill nor eliminate it. In fact, chemicals can do more harm to the applicator and the environment! The best approach to controlling these unique organisms is to try changing the environment in which they grow. Slime molds and other such organisms will not grow well in dry situations. Little can be done to reduce the amount of rainfall we get, but irrigation systems can be adjusted to keep the mulch from becoming excessively wet on the surface. Another approach to controlling it is to rake and loosen the mulch chips to break it up. This will let air into the mulch so it can dry.

Wood chip mulches insulate soil from temperature fluctuations, protect trees from string trimmers and mowers and reduce problems of weeds in shrub beds. The slime molds that can grow in wood mulches are classed as ‘beneficial’ organisms and it’s possible that they feed on harmful plant pathogenic fungi found in bark and wood chips, thus controlling the harmful fungi naturally. Therefore, the benefits of slime mold to tree and shrub health outweigh the aesthetic problem of cauliflower-like blobs in the garden.

The following information was obtained from Nana Mejia, Horticulture Agent, The Plant and Pest Digital Library Project at Colorado State University Cooperative Extension.

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