Brand: Westland PF MPC + JI | Supplier: B&Q | Price: £0.17/litre
Personal observations
This is Westland’s mainstream peat-free multipurpose product with a John Innes addition, sold through B&Q. The John Innes element is intended to add mineral ballast and improve structure for potting-on use. In practice, the dominant character is still the wood-fibre base — you can see and feel the fibre fluff throughout the material, which is very characteristic of Westland’s approach across their range. The sieve result is telling: only 21% of material passes through 2mm, while 66% is retained in the 2–10mm fraction — confirming the fibrous character. Water retention is good at 3.7 times dry weight, and dry-down is fairly fast at 20 minutes. The John Innes addition does add some useful structure for repotting, but this is primarily a wood-fibre growing medium rather than a compost in the traditional sense. Good for pots and containers; less suited to seed trays or lawn work where fine texture matters.
Quick-test data (April 2026)
| Metric | Band | Value | Context |
|---|---|---|---|
| Bulk density (dry) | L | 0.14 g/ml | Very light — fibre-dominant despite JI mineral addition |
| Water held per g dry weight (WHC) | M | 3.7× | Upper-mid range — fibre structure contributing |
| Dry-down time | — | 20 min | Fast — fibre releases water readily |
| Sieve: <2mm fraction | — | 20.6% | Low — one of the coarser profiles in the test group |
| Sieve: 2–10mm fraction | — | 65.9% | Very high — fibre dominant |
| Sieve: >10mm fraction | — | 7.1% | Low-moderate |
| Price per litre | Mainstream | £0.17 | B&Q retail — bought in store, no P&P |
WHC is above the baseline wood-fibre expectation, likely assisted by the JI compost fraction adding some humic binding. However the fast dry-down confirms this is primarily structural/fibre water retention rather than chemically bound moisture.
B&Q in-store price only — purchasing online adds delivery cost and is not recommended for bulk compost. For an explanation of why brands offer multiple product types at different price points, see our FAQ.
Comparative hands-on testing, April 2026. Consistent method across all 18 products. See methodology note.
At-a-glance rating breakdown
| Category | Weight | Score | Notes |
| Ease of use | 40% | 7.0 | Light, free-draining texture. |
| Composition & quality | 35% | 6.1 | Coir and wood fibre blend. |
| Sustainability | 25% | 4.9 | Peat-free by design. |
| Overall (weighted) | 100% | 6.5 / 10 | Retail-standard peat-free MPC. |
What we liked
- Light, easy-to-handle material.
- Widely available.
Points to consider
- Low inherent nutrient reserve.
- Limited soil-building capacity.
Overall impression: A practical peat-free compost designed for ease and accessibility rather than soil improvement.
