The Biggest Mulching Mistakes We See (And How to Avoid Them)

At Murray River Mulch, we've delivered mulch to thousands of gardens across Perth, and we've seen just about every landscaping mistake imaginable. The good news? Most of them are easy to avoid with a little know-how.

If you're investing time and money into your garden, here are the biggest mulching mistakes we see—and how to make sure your mulch works for you, not against you.

Mistake 1. Not Using Enough Mulch

This is by far the most common mistake.

Many people spread mulch so thinly that you can still see the soil underneath. While it might look like you've covered the area, a thin layer won't effectively suppress weeds, retain moisture or regulate soil temperature.

Our recommendation: Aim for a mulch depth of 50–75mm for most garden beds. This provides excellent weed suppression while still allowing water to penetrate the soil.

Mistake 2. Applying Mulch Too Thick

More isn't always better.

Piling mulch 150–200mm deep can restrict airflow to the soil, trap excessive moisture and make it harder for rain and irrigation to reach plant roots. It can also become a comfortable home for pests if left unmanaged.

Stick to the recommended depth and simply top it up when needed instead of continually piling more on.

Mistake 3. Mulching Right Against Tree Trunks

You've probably seen the famous "mulch volcano."

While it might look neat, piling mulch directly against tree trunks or plant stems can trap moisture against the bark, increasing the risk of rot and disease.

Instead, leave a small gap around the base of trees and larger shrubs to allow air circulation.

Mistake 4. Forgetting to Remove Existing Weeds

Mulch is fantastic at preventing new weeds from germinating—but it isn't magic.

If you spread mulch over established weeds, many of them will simply continue growing straight through.

Spend a little time removing weeds before mulching and you'll save yourself hours of maintenance later.

Mistake 5. Choosing the Wrong Mulch for the Job

Not all mulch is created equal.

Different projects call for different products.

For example:

• Decorative and dyed mulch is perfect for enhancing the look of garden beds but not so much for the health of your soil for plant growth. You would only see the most durable plants do well in these garden beds compared to a natural mulch that provides nutrients for even the most fragile of plants.

• Playground mulch is designed for shaded play areas but creates an extreme heat risk for your garden beds meaning you could risk overheating your plants and in direct sunlight in extreme conditions, can even become a fire risk for certain products.

• Coarser mulches are ideal for larger landscape areas where longevity is important. But they dont break down as quickly and therefore don't supply an extremely rich nutrient rich soil base due to the slow breakdown of the mulches nutrients into the soil. It may not be the best fit for germinating new plants or trees.

Choosing the right mulch from the start will give you better results and better value for money.

Mistake 6. Skipping Soil Preparation

Healthy gardens start below the surface.

Applying mulch over compacted, dry or nutrient-poor soil without first watering or improving the soil means your plants won't get the full benefit.

Water thoroughly before mulching and consider adding a top soil to the soil underneath before mulching to ensure your plants are getting the full benefit of what mukch can do for your gardens.

Mistake 7. Not Refreshing Mulch

Mulch naturally breaks down over time—and that's actually a good thing.

As it decomposes, it contributes organic matter back into the soil. However, this also means the layer gradually becomes thinner.

A light top-up every 12–24 months will keep your garden looking fresh while maintaining all the benefits mulch provides.

Mistake 8. Buying Bags Instead of Bulk

This one might be a little biased…

We regularly meet customers who have spent hours loading, unloading and spreading dozens of heavy bags—only to discover they could have ordered bulk mulch delivered for a cheaper price. Yes! that right... I said cheaper.

Let us prove it to you.. the cheapest bag of mulch at your local Aussie well known hardware store (Im sure you can guess which one) is $5.97 for a 25L bag. theres 1000L in one cubic meter. meaning you would need around 40 bags. thats then $238.80. plus you have to haul 40 bags of mulch into the cart, through the checkout, out the store, into the car then into your gardens. All before you even get to spreading it!

OR

You could call Murray River Mulch for 1m3 delivered straight to your front verge for as little as $60 for the mulch and a $100 delivery fee (for zone 1 of delivery) and wallah! your mulch is at your door and ready to spread for $160 without even having to step foot out of your house!

Bulk delivery is way more economical, reduces plastic waste, keeps your wallet more full AND saves your back from unnecessary lifting.

Mulch Is More Than Just Decoration

Quality mulch helps:

• Retain soil moisture.

• Suppress weeds.

• Regulate soil temperature.

• Improve soil health as it breaks down.

• Reduce erosion.

• Create a neat, professional finish.

When installed correctly, it's one of the simplest and most cost-effective improvements you can make to your garden.

Need Help Choosing the Right Mulch?

At Murray River Mulch, we're always happy to help you choose the right product for your project. Whether you're refreshing a small garden bed or tackling a complete landscape makeover, our team can recommend the best mulch and arrange fast delivery throughout Perth and surrounding suburbs.

Browse our premium range online or get in touch today—your garden (and your future self) will thank you.

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