Brand: Miracle Gro PF, Moisture control | Supplier: B&Q | Price: £0.17/litre
Personal observations
The Moisture Control product is the premium line in Miracle-Gro’s peat-free range, and it stands out immediately. It is visibly wetter than any other product on opening — dark, heavy in the hand, and it forms a strong sticky ball. Water-holding capacity is the highest of any mainstream compost in the test at 5.67 times dry weight — only the specialist Fertile Fibre coir product exceeds it. The sieve profile is dominated by the 2–10mm fraction at 72%, with only 18% passing through 2mm — the moisture-holding fibre structure is doing the work here. One caveat: the product was noticeably wetter at the start of testing than others, which may have slightly affected the dry-down measurement. Even accounting for that, 30 minutes is a good result. This is a genuinely strong performer for hanging baskets and containers where moisture retention between waterings matters. The darker colour and cohesive texture suggest a richer input mix than most — possibly including a wetting agent, which would be consistent with the product name.
Quick-test data (April 2026)
| Metric | Band | Value | Context |
|---|---|---|---|
| Bulk density (dry) | L | 0.12 g/ml | Very light — fibre-dominant structure |
| Water held per g dry weight (WHC) | H | 5.7× | High — above typical organic range |
| Dry-down time | — | 30 min | Moderate — better retention than WHC figure alone suggests |
| Sieve: <2mm fraction | — | 18.4% | Low — coarse fibre profile |
| Sieve: 2–10mm fraction | — | 72.0% | Very high — highest mid-fraction in test group |
| Sieve: >10mm fraction | — | 6.8% | Low-moderate |
| Price per litre | Mainstream | £0.17 | B&Q retail — bought in store, no P&P |
High WHC likely assisted by a wetting agent — consistent with the product positioning and the notably wet condition at bag opening. The 30-minute dry-down confirms the water is genuinely accessible to plants rather than being purely structural capillary retention. Better real-world moisture behaviour than the dry BD alone would suggest.
B&Q in-store price only — purchasing online adds delivery cost and is not recommended for bulk compost.
Comparative hands-on testing, April 2026. Consistent method across all 18 products. See methodology note.
At-a-glance rating breakdown
| Category | Weight | Score |
| Ease of use | 40% | 6.7 |
| Composition & quality | 35% | 6.7 |
| Sustainability | 25% | 6.7 |
| Overall (weighted) | 100% | 6.7 / 10 |
What we liked
- Easy to use.
- Widely available.
Overall impression: I liked the feel of this – sticker than most.
