Gravel vs Bark Mulch: Which Is Better for Garden Borders?
Both are popular ground covers for borders and planting areas, but they perform very differently over time. Here’s an honest comparison to help you choose.
Full Comparison
| Feature | Decorative Gravel | Bark Mulch |
|---|---|---|
| Cost (per m² at 50mm depth) | £3–£8 | £2–£5 |
| Lifespan | 10+ years | 2–3 years |
| Maintenance | Very low (occasional rake) | Medium (top-up every 2–3 years) |
| Weed suppression | Excellent (with membrane) | Good (but degrades) |
| Drainage | Excellent | Good |
| Soil moisture retention | Moderate | Excellent |
| Nutrient addition | None | Yes (decomposes into soil) |
| Slug/pest harbour | No | Yes |
| Appearance change over time | Minimal (stays consistent) | Fades and decomposes |
| Dog friendly | Yes | Potential toxicity (cocoa bark) |
| Cat friendly | Depends on size (20mm+ deters cats) | Cats dislike bark texture |
| Wildlife benefit | Low | Moderate (habitat for insects) |
| Wind resistance | Excellent (heavy) | Poor (light bark blows) |
When Gravel Is Better
- You want a low-maintenance, permanent solution
- Drainage is important (clay soils, damp areas)
- Slugs are a problem (bark harbours them, gravel doesn’t)
- You want clean, consistent appearance year-round
- Windy location (bark blows away, gravel stays)
- Modern or Mediterranean garden style
When Bark Is Better
- You want to improve soil quality over time (bark decomposes into humus)
- Budget is tight (cheaper initially, though long-term cost is higher)
- Woodland or cottage garden style
- You want maximum moisture retention in dry summers
- Around acid-loving plants (bark gradually acidifies soil)
The Long-Term Cost Reality
Bark is cheaper to buy initially (£2–£5/m²) but needs replacing every 2–3 years. Over 10 years, you’ll spend roughly £10–£25/m² on bark. Gravel costs £3–£8/m² once and lasts 10+ years with no replacement needed.
Over a decade, gravel is roughly half the cost of bark despite the higher upfront price.
Can You Combine Them?
Yes. Many gardeners use gravel for paths and seating areas (firm, clean surface) with bark in planting borders (better for soil and moisture). The key is to install a clear boundary (edging strip) between the two — otherwise bark debris migrates into gravel and looks messy.
Calculate Your Gravel Quantities
Decided on gravel? Our free calculator works out exact tonnage, bag counts, and cost estimates for your borders, paths, or driveways.
Open Gravel CalculatorFrequently Asked Questions
Is gravel or bark better for borders?
Does bark mulch attract slugs?
How long does bark mulch last?
Can I put gravel on top of bark?
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