CalculatorMulchWhat does mulching cost me every year?
Mulch is not a one-off. Organic mulch breaks down and needs topping up every year or two, which is the number that decides between bark and gravel.
What the yard needs this month
MonthlyOne job a month, with the depth and the volume it actually needs. No plant catalogues, no upsell — just the material side of the garden.
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How this works
How often mulch needs topping up
Organic mulch loses roughly an inch a year to decomposition.
| Material | Top up every | Full replacement |
|---|---|---|
| Shredded hardwood bark | 1 year | Rarely needed |
| Pine bark nuggets | 2 years | Rarely needed |
| Wood chips | 1 to 2 years | Rarely needed |
| Straw | Every season | Every season |
| Gravel or stone | Never | Only if contaminated |
| Rubber mulch | Never | 10 years or more |
Decomposition rate depends on climate, on how finely the material is ground, and on whether it sits on bare soil or fabric.
Frequently asked questions
How often does mulch need replacing?
Organic mulch loses about an inch a year to decomposition. Topping up annually to keep two to three inches is typical; a full replacement is rarely needed.
Is gravel cheaper in the long run?
Usually yes on materials, because it does not decompose. It also does not feed the soil, is unpleasant to plant through, and holds heat. The cost comparison is the easy part of that decision.