Mulch Types Compared: Hardwood, Bark, Cedar, Straw and Rubber
Comparison
| Type | Lasts | Weight per cu yd | Best for |
|---|---|---|---|
| Shredded hardwood | 1–2 seasons | ~800 lb | General beds, slopes — knits together and stays put |
| Bark nuggets | 2–3 seasons | ~600 lb | Flat beds and paths; floats and washes away on slopes |
| Shredded cedar or cypress | 2–3 seasons | ~600 lb | Where longevity and scent justify the premium |
| Wood chips (arborist) | 2–3 seasons | ~600 lb | Paths, trees, large areas — often free from tree crews |
| Pine straw | 1 season | ~300 lb | Azaleas, camellias, blueberries; very light to handle |
| Compost | 1 season | ~1,100 lb | Feeding the soil; poor weed suppression on its own |
| Straw | 1 season | ~250 lb | Vegetable beds — check it is straw, not hay full of seed |
| Gravel and stone | Indefinite | ~2,800 lb | Xeriscape, drainage strips; adds no organic matter and stores heat |
| Rubber mulch | Indefinite | ~1,500 lb | Playgrounds; does not decompose or feed the soil |
The properties that actually matter
- Does it stay where you put it? Shredded material knits into a mat and holds on a slope. Nuggets float in heavy rain and end up on the lawn or in the drain. This single property matters more than colour or species for most beds.
- How fast does it break down? Fast decomposition means annual topping up, but it also means organic matter going into the soil. Slow-rotting cedar and cypress look tidy for longer and feed the soil less.
- Weight, if you are hauling it. Pine straw is a quarter the weight of hardwood mulch per cubic yard, and gravel is three and a half times heavier. That decides how many trips your vehicle makes.
- What it does to soil pH. The effect of most wood mulches on soil pH is small and slow — pine bark and pine straw are mildly acidifying, which suits acid-loving shrubs but is not a substitute for actually amending soil.
Dyed mulch: what you are buying
Dyed black and red mulches are typically ground wood — often recycled pallets or construction scrap rather than bark — coloured with iron oxide or carbon-based dye. The dye is not the concern that internet rumour suggests; the substrate is what varies. Ground pallet wood breaks down fast, has little nutritional value, and can temporarily draw nitrogen from the soil surface as it rots. Fine for a tidy commercial-looking bed; less good as a soil improver.
Rubber mulch: the honest assessment
It never breaks down, so you buy it once, and it works as a playground fall surface where depth and impact absorption are the point. As a garden mulch it contributes nothing to soil structure, becomes very hot in sun, is difficult to remove once mixed with soil and leaf litter, and can be a fire concern in dry climates. For a planted bed, organic mulch does more for less.
What this means for your order
Volume is volume — a cubic yard of any material covers the same 108 sq ft at 3 in deep, so switching type does not change how much you need, only what it weighs and how often you top it up. Set the material in the mulch calculator to get a realistic weight before you load a vehicle, and enter both bagged and bulk prices to see which route is cheaper for the type you have chosen.
Get the cubic yards, the bag count and the approximate weight for a bed at any depth — and see straight away whether bagged or bulk delivery is the cheaper way to buy it.
Frequently asked questions
What is the best mulch for most gardens?
Shredded hardwood is the sensible default: it knits together so it stays put even on a slope, suppresses weeds well, breaks down into the soil, and is usually the cheapest per cubic yard. Cedar and cypress last longer if you want to top up less often.
Which mulch lasts the longest?
Among organic mulches, cedar, cypress and bark nuggets last two to three seasons against one to two for shredded hardwood. Gravel and rubber last indefinitely but contribute nothing to the soil.
Is dyed mulch safe?
The colourants used in commercial dyed mulch are generally iron oxide or carbon based and are not the main issue. What varies is the wood underneath, which is often ground pallet or scrap rather than bark — it breaks down quickly and adds little to the soil.
Is rubber mulch a good idea for garden beds?
It works as a playground surface but makes a poor garden mulch: it adds no organic matter, gets very hot in sun, is hard to remove once mixed with soil, and can be a fire concern in dry climates.
- How Deep Should Mulch Be?
- Bulk or Bagged Mulch: Which Is Actually Cheaper?
- When Should You Mulch? Spring, Fall, and Why Timing Matters
- How Much Topsoil Do I Need?