Mulch has been called a friend of gardener’s—and for a good reason. In winter, mulch protects bare soils, prevents erosion, and protects plants. In the spring, mulch locks in moisture, suppress weeds and feeds the soil. Learn how to mulch, when to mulch, and how to use many different types of mulch in your garden.

Mulching is a fundamental part of the gardening of plants that look beautiful and productive throughout the year. If you don’t know how to mulch, it’s essential to learn when to mulch, the right mulch depth, and the right mulch type.

What is mulch?

At its simplest, mulch is any material that covers the soil’s surface. In nature, mulch is simply fallen leaves and plant debris. In the garden, mulch can also include compost, wood chips, rotted manure, cardboard, or even seaweed.

It’s only recently that we have come to appreciate the sustainable and ecological benefits of mulch. Done correctly, mulching feeds nutrients to our soil’s living microorganisms, and waste from these tiny microbes creates a healthier soil structure for plants, limiting compaction.

Types of mulch

The perfect mulch should be thick enough to block the growth of weeds, but light and open enough to let water and air to enter the soil. Factors to consider when buying mulch are cost, availability, ease of use, and what looks like in the garden. There are a lot of different colour and texture materials to choose from. Organic and inorganic mulches can be easily used in the garden.

Organic mulches

Organic mulches are natural forms of leaves, trees, grass, and other plant material, mostly from your yard. They emulate nature, breaking down steadily over time. The benefit is that they are merely applying organic matter to the soil. The downside is that they have to be replenished regularly.

Compost is readily available and breaks down efficiently to strengthen the soil. If you don’t have your own, cities also make it available from a leaf composting plant. The downside is that it needs to be replenished and can produce weed seeds.

Shredded leaves and leaf mould are readily available and, if chopped, eventually break down and feed the soil with valuable materials. The disadvantage is that leaves can mat if wet, which reduces the oxygen and moisture in the ground. Avoid matted layers of wet leaves.

Chipped bark or shredded bark can also be used as mulch. Softwood bark is appealing, avoids compaction, and eventually breaks down. Hardwood bark is appealing, but it breaks down quickly and needs to be carefully composted to avoid sour mulch and pests.

Straw and salt marsh hay are cheap and useful in covering; however, they decompose more readily, can shelter rats, and are quickly swept away by the wind.

Grass clippings are available but should be dried first or scattered thinly to prevent them from being a hot, slimy, smelly mess. Often, you can’t use lawn clippings that are contaminated with pesticides in a vegetable garden.

Pine needles are desirable and have a safer position than most mulches. They’re sluggish to break down, but don’t think about adding acidity to the soil.

Inorganic mulches

Black plastic mulch tends to warm the soil in season, decreases water loss, and is handy. This will cause a notable difference in the short growing seasons. It is not permeable, though, because it is more difficult to water; it also breaks down when exposed to sunshine and the soil under plastic gets very hot in the middle of summer if it is not shaded by leaves or filled by another mulch.

Silver plastic mulch excels as the soil is heated in spring but does not control weeds; the ground gets much hotter with transparent plastic in midsummer, and the plants will be killed if the plastic is not shaded.

Crushed stones, asphalt, marble, or brick chips create a permanent mulch around shrubs and trees. That said these mulches are costly, difficult to transport, and they can get into the grass. Weed seeds and dirt will also make their way through the stones; the underlayer of the landscape cloth helps to avoid this.

Landscape fabric smothers weeds while allowing air, manure, and water to flow through and through the soil. They are treated to prevent decomposition and help preserve soil moisture. It’s essential to fasten the fabric down so that perennial weeds don’t drive it up.

Ten tips to mulch your garden

Using the mulch as a decoration: Mulching can help to build healthier lawns, but it also has an aesthetic value. Choose a colourful mulch that complements the exterior colours of your home with brick, mortar, stucco, and siding. E.g., brownish/red pine mulch is suitable for brick buildings, says Jeremy Becker, owner of FireFly Landscapes in Kansas City. Using a dark mulch will contrast with flowers, enhancing the look of your landscape. Mulch can also be applied to improve the pattern and setting of your landscape.

Do look at your entire landscape: If you want to plan your gardens so that your shrubs cover all the soil and you have a full vegetative cover then use a mulch to regulate the moisture. Choose a mulch type suitable for your whole landscape.

Just clean it up: If you re-mulch a bed, take some of the old mulch. Perhaps mulch can be added to the beds three to four times, so digging out some of the mulch that has been built up over time.

Do the thickness tweak: When you come up to the ground, like a pavement, a stone’s leg, or a tree root, slim it out. There’s no point in making a mound of mulch next to a tree vehicle. You’re going to tape it off.

Try a different mulch: There are a variety of textures, beginning with alternatives such as pine straw and shredded hardwood bark. If you’re looking for an unusual look and need to refresh your mulch, consider some choices, such as cocoa bean shells (they smell nice too), nut hulls, reclaimed pallets that are ground, and even seaweed.

Do not skip the bare soil: Researchers are observing that mulching has notable environmental benefits. Having bare soil on your lawn will cause erosion and sediment runoff; mulching can help control erosion. Researches say that bare soils lose about five times as much sediment as soils covered with mulch.

Do not use too little or too much mulch: About 3 inches of mulch twice a year is recommended for beds. Mulching with the correct amount and at the right time will help to avoid weeds and preserve moisture, which will reduce your irrigation needs. One exception is the use of pea gravel mulch or inorganic mulch; then you could get away with using just two inches. Another consideration is that you have a bed of herbaceous plants that may be too thin for 3 inches of mulch.

Don’t forget about your trees: Place mulch around the base to cover your trunk, particularly if you have younger trees. Mulch rings make a defensive area to reduce the danger from other plants and hold the mowers away.

Don’t presume that you need anything beneath: Some people will choose to use plastics or geotextiles, such as landscape cloth, to distinguish those mulches, such as inorganic stone mulch, from the soil. There is a misconception that black plastic is going to hold the weeds down. But applying a layer of plastic or landscape fabric could cause more water to run and prevent your garden from getting a smooth, streamlined look.

If you’re using an organic mulch that melts down, like shredded hardwood bark, stop landscape fabric because you want the mulch to be in contact with the soil and make it healthier. Plastic or landscape fabric could block water and rain from touching the soil and could potentially raise the runoff. Weeds could also evolve into a landscape cloth.

Don’t use the wrong mulch: The greatest pitfall is to get your mulch from an unreliable source. E.g., mulch may be supplied with noxious weed seeds when it did deposit next to a field of weeds. It would be best if you bought mulch from a trusted dealer to avoid any future problems.

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