Quick answer: river rock earns its place in four jobs: garden edging, pathways, dry creek beds that move water away from your house, and the ground around water and fire features. Lay it 2 to 3 inches deep over landscape fabric, and keep it away from heat-sensitive shrubs.
This guide covers where river rock works, how to build a dry creek bed, which stone size to pick, and an honest look at when mulch is the better choice.
Where to Use River Rock in Landscaping
Garden edging. A single or stacked row of stones gives beds a clean border that never rots or needs re-cutting. It also keeps soil from washing onto the lawn in heavy rain.
Pathways. Smooth stones make a comfortable, natural-looking walking surface. Use larger stones to frame the path and smaller pebbles as infill. Paths of rock pair well with pavers, and our guide to backyard interlock design shows several combinations.
Water features. River rock looks like it belongs near water because in nature it comes from water. Use it to edge a pond, line a stream, or hide the liner around a waterfall. If your feature has a pump, our pond pump sizing guide covers the mechanical side.
Fire features. A bed of stone under a fire bowl protects the surface below and frames the feature. See our comparison of fire pits, fire bowls, and outdoor fireplaces before you pick one.
Looking for broader inspiration first? Our low maintenance front yard ideas cover the whole yard, not just stone.
How to Build a Dry Creek Bed for Drainage
A dry creek bed is a stone-lined channel that looks like a stream and carries rain runoff away from your foundation. In the GTA it earns its keep every March, when snow melt has nowhere to go.
- Mark the route. Follow the natural slope from your downspout or wet spot toward a safe outlet, with gentle curves.
- Dig the channel. A shallow trench about twice as wide as it is deep works for most yards. Grade it so water always moves away from the house.
- Lay landscape fabric. It stops weeds and keeps stone from sinking into the soil.
- Add a base of pea gravel. A thin layer locks the larger stones in place.
- Place the stone. Set boulders at the curves first, then fill with 1 to 3 inch river rock. Mix sizes so it reads as a natural stream.
Planting the edges with grasses or perennials softens the line and makes the bed look like it was always there.
What Size River Rock Do You Need?
Size decides both the look and the job. This is the sizing we walk customers through at the counter.
| Stone size | Best use | How deep to lay it |
|---|---|---|
| Pea gravel (6 to 10 mm) | Base layers, between stepping stones | About 2 inches |
| 3/4 to 1 inch | Edging, bed cover, path infill | 2 to 3 inches |
| 1 to 3 inch | Dry creek beds, borders | About 3 inches |
| 3 to 5 inch | Creek edges, accents | Single layer |
| Boulders | Anchors at curves, focal points | Set partly into the soil |
For coverage, one cubic yard of stone covers roughly 100 square feet at 3 inches deep. Measure your area, and we can convert it to yards or bags at the store.
River Rock vs Mulch: Which Is Better?
Short answer: use river rock for structure and drainage, and use wood mulch around plants you want to thrive. Around trees and shrubs, stone has real downsides that extension researchers have documented.
| Factor | River rock | Wood mulch |
|---|---|---|
| Replacement | Lasts decades | Top up every 1 to 2 years |
| Weed control | Good over fabric | Good at 3 inches deep |
| Soil health | Adds nothing | Feeds soil as it breaks down |
| Summer heat | Absorbs and radiates heat | Keeps roots cooler |
| Best spot | Paths, edges, drainage, feature bases | Planting beds, around trees |
“Rock mulch is a heat trap. For heat-sensitive plants like birch, mountain ash and hosta, the use of rock mulch may contribute to premature death.”
Tom Kalb, Extension Horticulturist, North Dakota State University Extension
That is why we steer customers toward stone for paths and drainage, and toward soil and mulch for planting beds. Selling you the right material beats selling you more of the wrong one.
How to Lay River Rock
Good prep is most of the job. Clear the area, level it, and start with fabric.
“For optimum weed control, it is advisable to place a layer of landscape fabric (not sheet plastic) on the soil surface before installing rocks.”
Angela O’Callaghan, University of Nevada, Reno Extension
After that, upkeep is light. Rinse the stones once a season to keep their colour. Blow leaves off in fall before they break down between the rocks. In winter, mark rock paths so snow clearing does not scatter stone onto the lawn. Freeze and thaw cycles that destroy bagged mulch do nothing to stone, which is why rock wins on lifetime cost in Ontario.
Where to Buy River Rock in Mississauga
Sid’s carries river rock in every size in this guide, from pea gravel to boulders, in bulk and in bags. Browse our aggregates range, or visit us at 6000 Ninth Line in Mississauga to see the stone before you buy. Not sure about quantities? Contact us with your measurements and we will spec it for you.
River Rock Landscaping FAQs
How much river rock do I need?
Multiply length by width by depth. One cubic yard covers about 100 square feet at 3 inches deep. A typical 20 by 4 foot border at 3 inches needs roughly three quarters of a yard. Bring your measurements in and we will do the math with you.
Do I need landscape fabric under river rock?
Yes, in almost every case. Fabric blocks weeds from below and stops stone from sinking into the soil, which means you buy stone once instead of topping it up. Use woven fabric, not plastic sheeting, so water can still drain through.
Does river rock stop weeds?
It reduces them, but no cover stops weeds completely. Wind still drops soil and seeds between stones over time. Fabric underneath plus an occasional rinse keeps growth to a few minutes of pulling a season.
Can I put river rock around trees and shrubs?
Be careful here. Stone absorbs heat and gives nothing back to the soil, and NDSU Extension links rock mulch to stress in heat-sensitive plants like birch and hosta. If you use it near plantings, leave a gap at the trunk and prefer wood mulch over the root zone.
