Mulching Around Trees and Shrubs Without Hurting Them

Good mulch protects a tree. Bad mulch slowly kills it. The difference comes down to how you handle the base of the trunk, how deep you go, and whether you actually clear out the old buildup before you dump new material on top.

Most of the tree damage I see in Fairhope yards isn't from storms or bugs. It's from years of mulch piled up against the trunk like a volcano.

Why does mulch piled against the trunk hurt a tree?

Tree bark is built to be exposed to air. When you bury the base of the trunk under mulch, you trap moisture right against the bark and keep it wet all the time.

Down here in Baldwin County, we get plenty of humidity and rain, so that trapped moisture doesn't dry out. The bark starts to break down, roots grow up into the mulch instead of down into the soil, and you end up with rot and girdling roots that choke the tree from the inside.

You've probably seen the "mulch volcanoes" around parking lots and newer subdivisions. They look tidy the day they're done. A few years later the tree is struggling and nobody connects the two.

The fix is simple. Mulch should sit like a doughnut, not a volcano. Keep it pulled back off the trunk so you can see the flare where the tree widens out at the base.

How deep should mulch actually be?

Deep enough to hold moisture and block weeds. Not so deep that water can't reach the roots and the soil can't breathe.

When mulch gets too thick, rain runs off the top or soaks into the mulch itself and never makes it down to where the roots are. It can also stay soggy underneath and turn into a matted layer that sheds water instead of holding it.

Here's the part people miss. If you already have old mulch in the bed, you don't just keep stacking new stuff on top of it every year. That's how beds creep up to six or eight inches deep over time.

Before I lay fresh mulch, I check what's already there. Sometimes it just needs a light refresh. Sometimes the old layer has crusted over and needs to be broken up or pulled back first so the new mulch actually does its job.

How should mulch go around shrubs specifically?

Shrubs follow the same rules as trees, just on a smaller scale. Keep the mulch off the stems and base, and keep the depth reasonable.

With shrubs I pay attention to the drip line, which is the area of soil out to where the outer branches reach. That's where most of the feeder roots are working, so that's the ground you want covered and protected.

I also watch for mulch smothering low branches or getting packed up into the crown of tight, dense shrubs. On azaleas and other bushy plants that are everywhere around Fairhope, that trapped moisture in the base leads to the same rot problems you get on trees.

What kind of mulch works best around here?

That depends on the bed, the plants, and the look you're after. Around Fairhope I install both mulch and pine straw, and each has its place.

Pine straw is light, it knits together and stays put on slopes, and it's a natural fit for the pines and acid-loving plants we grow all over Baldwin County. Mulch gives you a heavier, more finished look and tends to hold longer in flat beds.

For mulch installation on Fairhope trees and shrubs, I look at drainage, how much sun the bed gets, how steep the ground is, and what's already planted before I recommend one over the other. A bed on a slope down toward Mobile Bay behaves differently than a flat bed tucked against the house.

If you're not sure which fits your yard, that's exactly the kind of thing I'd rather look at in person than guess at.

When does mulch need refreshing?

Mulch breaks down. That's part of the job, it feeds the soil as it goes. But once it's thinned out, faded, or matted down, it stops holding moisture and weeds start pushing through.

Our long warm season and heavy rain speed that breakdown up compared to colder climates. A bed that looked full in spring can look tired and washed thin by late summer.

When I refresh a bed, I don't just add a fresh top layer and call it done. I pull weeds, check the depth that's already there, clear mulch back off any trunks and stems, and even things out so the new material sits right.

That's the difference between a bed that just looks better for a week and one that actually protects your plants and stays clean for the season.

What drives the cost of mulching around trees and shrubs?

The size of the beds, how many trees and shrubs you're working around, and how much old mulch or weed cleanup has to happen first all move the number. A brand new bed is different from one that's been buried under years of buildup.

Whether you want mulch, pine straw, or a mix matters too, along with how tight the access is for hauling material in.

Because those things vary so much yard to yard, quoting you sight unseen would just be a guess. Let me walk the property and I'll give you a straight number for your actual beds.

When to Give Me a Call

If your trees have mulch mounded up the trunk, or your beds are looking thin and weedy, I can come take a look and tell you what they actually need. No volcano mulching, no piling new material on old, just beds that protect your plants and look clean.

Call or text (251) 656-4220 and we'll set up a time for me to walk your yard here in Fairhope.