Walk into any garden center and you'll hear the same question over and over: should I use stones or mulch? As a decorative stone supplier that has shipped thousands of orders across Canada and the U.S., we obviously have a soft spot for stone. But we also know it's not always the right call. Some projects genuinely need mulch, and pretending otherwise would waste your time and money.

This guide breaks down the real differences so you can pick the material that fits your project, your climate, and your budget.

What You're Actually Choosing Between

The terms "stone" and "mulch" each cover a wide range of products, and the specific type matters more than most people realize.

Landscaping stones include river rock (smooth, rounded, great for dry creek beds), crushed granite (angular, compacts well for pathways), pea gravel (small and affordable for large areas), lava rock (lightweight, excellent drainage), and marble chips (bright white, decorative accent). Each behaves differently in the landscape. River rock won't compact the way crushed granite does. Lava rock weighs roughly half as much as river rock per cubic foot, making it easier to install but more prone to displacement in heavy rain.

Mulch comes in organic and inorganic varieties. Shredded hardwood is the most popular and breaks down within 1 to 2 years, feeding nutrients back into the soil. Cedar mulch resists insects better than most alternatives. Pine bark nuggets are chunkier and last longer but can float away in heavy rain. Rubber mulch, made from recycled tires, doesn't decompose at all but adds no soil benefit and can overheat in direct sun.

The Real Cost Breakdown

Here's where most comparison articles get lazy with vague claims like "stones cost more upfront." Let's put actual numbers to it.

For a typical 100-square-foot garden bed, mulch costs roughly $2 to $5 per square foot installed at a 3-inch depth. Decorative stone runs $5 to $15 per square foot depending on the type, with river rock on the lower end and polished pebbles at the higher end. That's a significant difference on day one.

But mulch needs replacing every 1 to 2 years. Stone doesn't. Run the math over five years and the picture flips. You'll spend $600 to $1,500 on mulch for that same 100-square-foot bed (three to five applications), while stone is a one-time $500 to $1,500 investment. By year three, most stone installations have already paid for themselves compared to the cumulative cost of mulch.

How Each Material Affects Your Plants

This is the section where we need to be honest, because stone has real drawbacks that matter if you care about plant health.

Mulch is genuinely better for most plantings. As organic mulch decomposes, it releases nitrogen, potassium, and other nutrients directly into the soil. It keeps moisture locked in by reducing evaporation, and it insulates roots from temperature swings. A University of Wisconsin study found that properly mulched trees can nearly double their growth rate compared to unmulched ones.

Stone doesn't offer any of those benefits. Worse, it can work against your plants. Rocks absorb and radiate heat from the sun, raising soil temperatures around root zones. Over time, stone can shift soil toward a more alkaline pH, which is a problem for acid-loving plants like azaleas, blueberries, and most conifers. And because stones are permanent, organic matter never gets returned to the soil beneath them.

That said, some plants thrive with stone mulch. Succulents, lavender, rosemary, and other Mediterranean-type plants prefer the drier, warmer conditions stone creates. If you're building a xeriscape or rock garden, stone is the obvious match.

Maintenance: What Each Option Actually Demands

Mulch is simple to install (just spread and rake) but demands ongoing attention. You'll need to top it up every spring, watch for fungal growth in humid conditions, and know that certain wood mulches attract termites, carpenter ants, and beetles. If your mulch layer thins below 2 inches, weeds push through quickly.

Stone requires more effort upfront but very little after that. The key is proper installation: always lay landscape fabric underneath before placing stone. Without it, stones sink into the soil within a year or two and weeds find their way through. With fabric and a 3- to 4-inch stone layer, weed growth drops dramatically. You'll still pull the occasional weed that roots in debris between the stones, but it's far less work than annual mulch replacement.

One thing to plan for: if you ever want to remove stones, it's a labor-intensive job. Mulch you can simply rake or till into the soil. Stones need to be shoveled out by hand. Choose stone only where you're confident about the long-term design.

Climate Considerations

Your local weather should heavily influence this decision. Here in Quebec, where our warehouse is based in Boisbriand, we deal with harsh winters, spring flooding, and hot summers. Customers in different climates face different trade-offs.

Cold climates (Canada, northern U.S.): Mulch insulates roots against freeze-thaw cycles, which is critical for perennials and young trees. Stone doesn't insulate at all. For planting beds in zones 3 through 5, mulch around the base of plants is usually the smarter choice. Stone works well for pathways, borders, and non-planted areas where insulation doesn't matter.

Hot, dry climates: Stone conserves water by eliminating evaporation from the mulch layer itself, but it also raises soil temperature. In desert climates like Arizona or Nevada, light-colored stones reflect more heat than dark ones. Avoid black lava rock in full sun areas where plants are close by.

Fire-prone regions: Stone wins hands down. It's non-flammable and creates defensible space around structures. Wood mulch, especially dry mulch in late summer, is a fire hazard.

Rainy or flood-prone areas: Heavier stones stay put during storms while lightweight mulch washes out. For slopes and drainage channels, stone is far more practical.

When to Use Each (and When to Combine Them)

Choose stone for: pathways and walkways, around fire pits and outdoor living areas, drainage solutions and dry creek beds, modern or minimalist garden designs, high-traffic zones where kids and pets cut through, and anywhere fire resistance matters.

Choose mulch for: garden beds with flowers, shrubs, or vegetables, around the base of trees (especially young ones), annual planting beds you redesign each season, and anywhere you want to improve poor soil over time.

Use both together: Many of our customers use mulch in their planting beds and stone for pathways, borders, and decorative accents between beds. This gives you the plant-health benefits of mulch where it counts and the durability of stone where you need it. A clean edge between the two materials, using metal or plastic landscape edging, keeps everything looking sharp.

Making Your Decision

The honest answer is that most landscapes look and perform best with a mix of both materials. Use each where it makes sense and your outdoor space will be better for it.

If you're ready to explore stone options, browse our landscaping stone collection or reach out to our team for help choosing the right stone type and calculating how much you need for your project.

Sources: University of Wisconsin Extension – Using Mulch in the Home Landscape; University of Minnesota Extension – Mulching the Landscape; USDA Natural Resources Conservation Service.