5 Mulch Mistakes To Avoid (And How To Do It Right)

Mulch is one of the easiest ways to make your yard look polished while doing some serious behind-the-scenes work—like holding moisture in the soil, stopping weeds from popping up, and keeping roots cool. But here’s the catch: mulch mistakes are more common than most homeowners realize. And when mulch is used the wrong way, it can damage the very plants you’re trying to protect.

Whether you’ve mulched for years or are just getting started, avoiding these five common errors can make a big difference in the health and appearance of your landscape.

1. Piling Mulch Against Tree Trunks (Also Known as “Volcano Mulching”)

This is one of the most common mulch mistakes out there—and one of the most harmful.

When mulch is piled high against the trunk of a tree, it traps moisture against the bark. That might sound like a good thing, but it’s not. Constant moisture invites rot, disease, and pests. Over time, the tree becomes stressed and weak, and may even die.

What to do instead:
Keep mulch at least 2 to 3 inches away from the base of the tree. Aim for a donut shape rather than a volcano. This allows air to circulate around the trunk and keeps the base dry.

2. Using Too Much Mulch

If a little mulch is good, more must be better, right? Not quite.

Over-mulching is a big mistake. When mulch is applied too thick—think 4 inches or more—it can create a barrier that keeps water and oxygen from reaching plant roots. That’s the opposite of what you want.

Stick to this rule:
Apply mulch in a layer about 2 to 3 inches thick. That’s enough to suppress weeds and hold moisture without suffocating your plants. Already have mulch down? Fluff it up with a rake before adding more. This helps break up any compaction and might reduce how much fresh mulch you need.

3. Ignoring Weeds Before Mulching

Throwing mulch over a bed of weeds won’t stop them. In fact, it’s one of the most overlooked mulch mistakes—giving weeds a cozy blanket to grow under.

Take time to prep the area first.
Pull or cut weeds at the root, and consider applying a layer of newspaper or cardboard underneath your mulch to block new ones from sprouting. Skip landscape fabric in most planting beds—it often causes more problems than it solves by trapping water or making it hard to plant later.

4. Not Replenishing Mulch Regularly

Mulch isn’t a one-and-done task. Organic mulch—like shredded bark, pine straw, or wood chips—breaks down over time. That’s actually a good thing. As it decomposes, it improves your soil. But it also means you’ll need to refresh it periodically.

Here’s what to watch for:
If the mulch looks faded, thin, or patchy—or if you can see bare soil—it’s time for a top-up. A light layer once a year is usually enough. Don’t just keep piling on more without checking the depth first.

5. Mulching Too Close to Plant Crowns and Stems

This mulch mistake is similar to volcano mulching, but it happens with shrubs, perennials, and flowers. When mulch touches the base of a plant, it traps moisture and creates the perfect conditions for rot and fungus.

Keep mulch a few inches away from the crown or stem of each plant.
This gives the plant room to breathe and helps prevent disease. Think of mulch as a protective ring—not a blanket to smother your plants.

Avoid These Mulch Mistakes for a Healthier, Happier Yard

When used the right way, mulch is one of the best tools you have to keep your landscape healthy and attractive. But the wrong approach—like over-mulching, smothering plant stems, or ignoring weed prep—can set you back.

By steering clear of these common mulch mistakes, you’ll create a landscape that thrives with less maintenance and fewer headaches.

Not sure if your mulch is helping or hurting your plants? Take a walk around your yard today and see if any of these tips apply. A few small changes can make a big impact.