mulch smell bad

Why Does Mulch Smell So Bad? (Here’s Why & How to Fix It!)

We all love to mulch our gardens, be it vegetables or flowers. It just looks nice and prevents excess water evaporation from the soil.

It also prevents most weed activity. But who would like a garden that smells bad? Is this because of your mulch?

Does mulch have manure in it?

No, mulch doesn’t have manure in it. It does smell like manure when it gets rotten or during the process of decomposition.

Anaerobic conditions in mulch

Commercially organic mulch is produced on a large scale and they are stored without proper care(in heaps). This sometimes creates anaerobic conditions.

They then are packed into air-tight packets further maintaining the same anaerobic conditions. This is the reason why your mulch may smell sulfuric.

Decomposition of Mulch

If you are using organic mulch in your garden, it undergoes decomposition. This is caused by fungal and bacterial entities present in the soil.

Actinomyces are the most common organisms that break down the mulch. Due to this breakdown, certain chemicals are released and they cause the odor.

decomposition of organic mulch

This decomposition provides plants with many nutrients. It doesn’t smell that bad, to be honest.

If you are using dyed mulch or black rubber mulch then it explains the bad smell. These kinds of mulches smell like chemicals and rightly so.

Dyed mulch or rubber mulch is not at all good for your soil. Black rubber mulch is even worse as it heats up during summer and causes water evaporation.

How Mulch Should Smell?

Mulch doesn’t release strong odors. Normal/healthy mulch should just smell organic. If you are using woody mulch, it would just smell like freshly cut wood.
By sniffing mulch you can tell if the mulch is good for your garden or actually toxic. Anaerobic conditions produce these toxins that will harm your plants.
Toxic mulch is dangerous to your plants. It can damage the foliage as it causes yellow/scorching spots on leaves. This can be attributed to the chemicals absorbed by the plant.
In most cases this is irreversible and that plant is as good as dead. Watering abundantly can help in some cases.

Does mulch smell go away?

If you’re using black rubber mulch/dyed mulch, there is not much you can do as it has chemicals after all.

If the smell is due to natural decomposition, you don’t need to worry about it at all. The smell will reduce in a couple of days.

How to get rid of the mulch smell?

You can get rid of the sulfuric smell by spreading out your mulch well so it gets aerated. This ensures your mulch undergoes aerobic breakdown.

mulch nuggets

If the smell is due to black rubber mulch/dyed wood mulches, the only way to get rid of the smell is by disposing of the mulch and replacing it with organic mulch.

If your organic mulch smells bad, it might be too moist and thus give out that rotten smell. Spread it out and let it take some air and sunlight so that it dries off.

Does rubber mulch smell go away?

Yes, the rubber mulch smell subsides after a few days of installation. Rubber mulch releases certain gases when heated which smell like new tyres.

The rubber smell is quite apparent in summer. Rubber mulch is full of unwanted chemicals and I’d not advise using ’em in the garden.

What is the best natural mulch?

There are many types of natural mulches. Each has its own benefits and characteristics. Let’s look at them one-by-one.

Pine straw as mulch

Pine straw can be an awesome mulch, it looks good and it’s natural. If you got a lot of pine trees in your area, this is the mulch to go for! It stays in place and doesn’t wash away.

Grass cuttings as mulch

In addition to preventing weed sprouts, and retaining moisture grass clippings supply adequate nitrogen and potassium to the soil.

It acts as a supplemental fertilizer. It also deters some pests. This type of mulch can be acquired easily.

grass cuttings mulch

Pine bark mini nuggets

This mulch is dark in color and is perfect for landscaping uses. This mulch also stays in place and doesn’t wash away. It keeps the moisture in the soil.

This mulch is perfect for potted plants as it avoids soil splashes when you water them. This organic mulch is great for plants as it decomposes and releases essential nutrients.

Cypress mulch

I don’t like this mulch especially as it stands out. It doesn’t look good for landscaping purposes. It is organic and actually helps your plants.

What is the safest mulch to use?

All of the above-mentioned mulches are completely safe and beneficial to your garden. You can use any of them moderately(2 inches).

Do not under any circumstances use red-dyed mulch or black rubber mulch in your garden. They are good for nothing and in addition, they are full of unwanted chemicals.

Should Old mulch be removed?

Yes if it’s a year old or more, you should probably dispose of it. Such old, decomposed mulch can cause root rotting and will harm the plants.

It’s better to keep just 2 inches of mulch in your flower/vegetable beds. A lot of mulch can suffocate your plants.

I’ve seen many gardens where they do not care much about getting rid of old mulch at all. This eventually kills the plants/trees.

Is mold in mulch dangerous?

You will see mold in your mulch when it has accumulated over the years. The moisture in your mulch is a nice habitat for fungi.

You might also find them when it rained a lot in your area. This is usually seen in shady areas of your garden.

All kinds of mold are dangerous to your pets. Black mold is especially harmful to humans and flowers. Just use a trowel to get rid of mold as soon as you notice them in your mulch.

You can avoid mold if your mulch is just enough and not piled up from ages.

Wrappin’ it up

Mulch smells only when it’s piled up and is experiencing anaerobic conditions. So it’s better to remove excess mulch when needed and add a new 2-inch layer of mulch.

Always use organic mulches and say no to artificial/processed mulches. Wishing you an odor-free garden!