Does Mulch Go Bad? (And How Do You Find Out?)

Does Mulch Go Bad? (And How Do You Find Out?)

Mulch is one of the essential additions to any garden because of its ability to conserve soil moisture and nutrients. Mulch also gives the garden an aesthetically pleasing look that is heartwarming.

YES, mulch can go wrong – be it the one you have in the garden already or the one in the bag you are yet to use, they can all go wrong.

You can tell your mulch is getting worse because of its rotten smell. But not to worry, you can still use the mulch even in that stinky state. Come along, and we will tell you how to do that.

How Important Is Mulching To Your Garden

How Important Is Mulching To Your Garden

The soil is a very part of gardening. It provides anchorage, moisture, and nutrient for growing plants, anything that protects the soil also protects the plants in the garden. Mulch is organic material like straw and wood chips applied on the soil surface to conserve the soil.

Mulch protects the soil by conserving the moisture which ordinarily would have been lost by evaporation. But with the mulch covering the surface of the soil and preventing the sun’s heat from reaching the soil, they reduce the amount of moisture lost from the soil.

In the same way, mulch keeps the water evaporation rate from the soil low, so it ensures that their lass nutrient is lost from the soil. Mulch holds the soil in place and also reduces water runoff from the soil surface, which usually leads to the leaching of nutrients from the soil.

The fact that mulch covers the surface of the soil means that it reduces the effect of agents of erosion, especially wind, and water. Hence mulching helps control erosion and also suppresses the weeds around your garden. The residual effects of inorganic fertilizers, heavy metals, and pesticides are removed with mulch on your soil.

One good reason why some use mulch in their garden is that it improves the aesthetic value of the landscape, especially with painted mulch which can beautify the whole scenery.

Does Mulch Go Bad?

Does Mulch Go Bad?

The answer to this question is affirmative. Mulch goes bad over time because, as organic materials, they can be acted on by microorganisms which will cause them to rot and decompose gradually.

Many soil bacteria and Worms come up to break down the bottom layers of mulch, which cause the mulch to go wrong and unfit for use, and so must be removed and replaced.

The good thing about mulch is that it must be worn smoothly. Organic mulch typically lasts 4 to 6 years – all things being equal. However, some mulch could become so bad after a year or two, and so must be replenished or replaced.

No matter how durable an organic matter is, it will decompose over time, which means it will need to be replaced eventually. There are a few factors that can affect the useful lifespan of and they include :

Climatic factors

A typical mulch may last five years or more under ideal climatic conditions. This figure, however, decreases if the weather condition, including rainfall and sun exposure, is too much.

Too much heavy rain will make the mulch consistently damp, thus creating the kind of environment that most fungi love. When these fungi invade the mulch, they decompose it,y causing it to go wrong. Too much sunlight can cause the mulch’s color, making them unappealing.

Mulch Colour

If you mulch your backyard because of how beautiful it makes your home look, then the look of the mulch is critical. Some colorless mulches may begin to turn gray after about a year. Even though they are not bad, they become unattractive, so you might have to replace the mulch soon enough.

The best bet for gardeners who add mulch to their garden for beautification is to get dyed mulch, which has a better color that doesn’t stay strong. When getting dyed mulch, ensure you don’t get cheap mulch that uses artificial processes to color the mulch, which can have some negative impacts as the dye penetrates your soil.

Mulch Size

The size of your mulch also impacts how long it lasts. For instance, bark mulch usually lasts longer the wood chips. Mulch that is smaller in size is more easily decomposed by microorganisms than those that are big, and this is because the smaller size means that the microbes have more surface area to act on. Secondly, small-sized mulch, like shredded mulch, sometimes gets washed away with rain.

How Do You Find Out A Bad Mulch

How Do You Find Out A Bad Mulch

It is so easy to find out if your mulch is going wrong because the sight and smell tell you. The first thing that you will notice about sour mulch is the smell.

Ordinarily, mulch should have no smell except the natural smell of the material it is made from. Once you perceive a strongly acidic or vinegar smell, it likely means your mulch is going rancid.

The looks of your mulch can tell you if your mulch has gone wrong. When you have large amounts of white mold throughout the mulch, especially if it is a mulch that is in a bag, it’s a sign that they are going wrong.

If these mulches begin to feel crumbly to the touch, they probably begin to decompose. Bagged bark mulch is more prone to developing mold, especially with poor aeration.

How To Maintain Your Mulch

The key to keeping your mulch from going bad on time is to maintain it properly. If you want to spend much less time and resources on mulch maintenance, you can opt for a considerable bark mulch that hasn’t been dyed. Mulch made from Cedar and Cypress bark is suitable because they decompose relatively more slowly.

You should always maintain the depth of your mulch at 2 to 3 inches, and they should be allowed to pile in one place, like beside a tree or plants, as this will keep the plants from getting the right amount of air they need.

Too much pile up of mulch is an invitation to insects and pests which can invade your garden. It also leads to the growth of mold and the proliferation of fungi.

You should replenish the mulch after a couple of years, especially if the depth of the mulch is less than an inch deep. You can mix the different textures of mulch with the soil to ensure enough air circulation.

Mulch in the shade can always go wrong, even on top of garden beds. To forestall this, you must treat the mold with the proper pesticide and ensure that the mulch’s depth is not more than 3 inches. It would be best to move the mulch around with a rake to allow more air into the pile and drain out more water from the mulch.

With your old mulch dumped in your compost bin together with other compost materials, especially the nitrogen-rich ingredients or green compost materials like leaves and hay thoroughly mixed in the bin, you can expect about six months for your mulch to be comply decomposed and turned into humus that can go into the soil.

Even though old mulch can be left on top of garden beds to break down, it is discouraged because it is just halfway to completely decomposing into a rich humus, a nutrient-rich addition to your soil. This partially decomposed mulch can damage your soil and disturb the plants’ roots in the soil. So, until the old mulch is completely decomposed, it is best not to add them to the soil.


Mulching is one of those regular gardening practices that help conserve our soil’s moisture and nutrient. Mulching also adds a touch of beauty to our garden, making it more welcoming.

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Mulch can go wrong, and you can tell from the acidic smell that emanates from them and their mold and grayish color. Instead of discarding sour mulch, convert them into organic fertilizer by composting them.

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