20mm Rundle rock is the most popular decorative rock size we carry — and it's easy to see why. The smaller sizing fills in tightly, looks clean and finished, and works in almost every landscaping application from garden beds to driveways. It's the same iconic Alberta rock as our 40mm Rundle, just sized down for finer detail work and tighter spaces.
Where it comes from
Rundle rock is named after Mount Rundle in the Canadian Rockies near Banff — right here in Alberta. The blend of granite, quartz, and schist gives it a natural range of light grey to dark charcoal tones that complement Calgary homes, whether you're going for a modern, clean look or a more natural alpine feel. No two loads look exactly the same, which is what makes it look so natural in a yard.
What it's used for
- Garden beds and flower beds — the most popular use in Calgary. The 20mm size fills in tightly around plants, suppresses weeds effectively, and looks sharp against green foliage and dark soil
- Pathways and walkways — smooth enough to walk on comfortably, stable enough to stay in place with regular foot traffic
- Driveways and parking pads — holds up well to vehicle traffic as a decorative surface layer over a compacted road crush base
- Low-maintenance front yards — replacing grass with Rundle rock is one of the most popular upgrades in Calgary right now. Zero watering, zero mowing, looks great year-round
- Rock gardens and xeriscaping — the natural Alberta tones are a natural fit for drought-tolerant and alpine garden designs
- Around trees and shrubs — cleaner look than mulch, longer lasting, and just as effective at protecting roots and retaining moisture
- Borders and edging — the 20mm size is small enough to tuck neatly along edges and curves
20mm vs 40mm Rundle — which size is right?
20mm fills in tighter and gives a more refined, detailed look — better for garden beds, borders, and areas where you want a clean finish. 40mm has a bolder, chunkier look and handles heavier traffic better. Many Calgary homeowners use 20mm in beds and borders and 40mm on driveways and open areas.
How much do you need?
For a 3-inch layer, budget roughly 1 cubic yard per 100 square feet. Use our free calculator for an exact number.
Where we deliver
Same-day bulk delivery across Calgary, Airdrie, Chestermere, Cochrane, Okotoks, and Langdon.
📞 403-510-9011