Multi-purpose Compost is the most popular growing media in the UK, with roughly 50–65 million bags sold each year.

Every compost on MultipurposeCompost.co.uk is rated using our MPC Balanced Scorecard v7 — a transparent, evidence-based way to compare composts on Ease of Use, Composition, and Sustainability.

Each brand is observed and compared against measurable indicators gardeners actually notice, like how easy it is to re-wet, how consistent the texture feels, or how long the mix stays productive.

Scores are combined and normalised to a clear 1–5 rating so you can make fair comparisons across products and price points.

Compost reviews vary because both the material and the reviewers vary. Batch differences, use-case expectations, and platform bias all play a role.

Compost bags all promise great results, but they don’t all deliver. Here’s how to spot the good ones in store — the same simple checks we use when testing products for our reviews. A few quick looks, squeezes and sniffs tell you far more than the label ever will.

Not all Multipurpose Composts (MPCs) are equal. Premium blends often cost more because they use higher‑grade ingredients and tighter process control, while budget composts trade consistency for price. Your best choice depends on your goal — seed sowing, potting, or general soil improvement. 

This page appears only after visitors enter the Reviews section. It’s written for everyday gardeners — explaining how compost quality is measured and why it matters, without jargon or alarmism.

It’s one of the most common gardener frustrations: two bags labelled “Multipurpose Compost” can behave completely differently. One drains perfectly; another stays soggy and lifeless. The reason lies in what “multipurpose” really means — and what it doesn’t.

Some Multipurpose Composts are very sustainable, others far less so. The difference lies in the ingredients, sourcing, and packaging.

Most compost bags say eco-friendly or planet-kind — but what’s really inside matters.

This page explains what “carbon footprint” means, why some composts are better for the climate than others, and how to spot the genuine green choices.

Not all composts labelled “organic” are certified. Learn what the logos mean — and which brands really carry Soil Association or OF&G approval. 

John Innes composts are classic soil-based growing media developed in the 1930s by horticultural scientists at the John Innes Horticultural Institution. They remain excellent for structured, long-term container growth — but differ completely from today’s soilless Multipurpose Composts (MPCs). The formulas are public domain and can be made at home using garden soil, sand and fertiliser; many modern “John Innes” bags are only loosely based on the original science.

Multipurpose Compost (MPC) is a modern, soilless, all-purpose mix designed for ease of use. John Innes 1, 2 and 3 are traditional, soil-based formulas graded by nutrient strength and tailored to plant growth stages.

Multipurpose Compost (MPC) is a flexible, ready-to-use growing medium designed for containers, raised beds, and general soil improvement. While convenient, it has limits — understanding how to use it well makes all the difference.

Bagged Multipurpose Compost doesn’t expire like food — but it does degrade over time. Most manufacturers recommend using unopened bags within 12–18 months of packing, and opened bags within 6 months.

Don’t just trust the marketing slogans — the most useful information is hidden in the small print. Check what’s inside the bag, how it’s certified, and whether its nutrient level and peat status match your intended use.

Multipurpose Compost works well straight from the bag — or blend in a little compost or biochar to create a living mix that holds water and nutrients for longer.

Using just MPC works short-term but needs more feed and water. Mix compost with soil for structure, moisture, and long-term fertility.

Yes — you can, and it’s usually a smart move.

Mixing MPC into your raised-bed soil makes it lighter, moister, and full of life.

Aim for one part MPC to one or two parts soil (around 33–50%), feed lightly through the season, and top it up each spring.

We’d strongly advise against it — unless the bag clearly says “for seeds.”

Most Multipurpose Composts (MPC) are made for growing plants, not starting them. They’re often too coarse and too strong for delicate seedlings.

Seeds need a fine texture, gentle moisture, and very little fertiliser. Standard MPCs are packed with larger fibres, added feed, and little microbial life. Result? Patchy germination, yellow leaves, or seedlings that keel over for no apparent reason.

There’s a knack to getting seeds going — and it starts with what they’re sitting in.

Measure the size of your bed or container, then match it to bag volume. Compost is sold in litres — so just multiply length × width × depth (in m) for cubic metres.

Use our simple volume rule to work out how many bags you’ll need

Yes — most MPCs only feed for a few weeks. After that, plants depend on you for nutrients.

Yes — with a little care. If you’ve got an unopened bag from last year, check it and carry on. If it’s compost that’s already done a season in pots or beds, don’t bin it — you can almost always bring it back to life.

Yes — indoors, clean compost wins every time.

• Best choice: Use MPC as a sterile, low-bug medium — feed monthly and repot yearly. 
• Avoid: Raw compost or “living” mixes — they invite gnats, mould, and disease indoors.

Learn the basics of watering, feeding and refreshing your plants so they thrive all season long.

👉 Confident care made simple for first-time compost users.

You can use Multipurpose Compost for light top dressing, but its benefit depends on your goal.\ If you want to smooth and refresh surfaces, fine-textured MPC works well.\ If you want to rebuild soil life and structure, choose a true compost such as PAS100 or well-matured DIY compost.

If your compost has dried out and water just runs off, here’s how to restore its structure, moisture, and function — including Tony’s natural humus suspension method.

Use a specialist compost when your plants genuinely need a very specific pH, nutrient, or drainage balance — for example, seeds, ericaceous plants, orchids, or citrus. For most other “for tomatoes/roses/vegetables” mixes, a good-quality Multipurpose Compost (MPC) plus the right feed at the right time will do the job just as well.

Most gardeners can safely re-use last year’s Multipurpose Compost (MPC) — provided it’s refreshed before planting again.

Short answer: No — not all plants or seeds thrive in standard Multipurpose Compost.

Most retail MPCs are nutrient-rich, fine-textured and microbially inactive, designed for convenience in pots and containers. But seedlings, acid-loving plants (like azaleas and blueberries), and some delicate ornamentals need different textures, lower nutrient levels, or a pH-adjusted base to avoid stress and root burn.

You can assess compost quality with a few simple at-home checks — no lab required. These tests help you tell if a mix is too wet, too woody, or poorly balanced before planting.

Yes — you can use Multipurpose Compost (MPC) as a short-term mulch, but it’s rarely the best or longest-lasting option. MPC breaks down fast, can crust when dry, and encourages weed growth. If you want moisture retention and weed suppression, go coarser — think bark, wood chip, or leaf mould.

Not exactly. All aim to grow healthy plants — but each brand takes a different route to get there. Learn what really changes between bags.

Compost can differ hugely between brands and batches. Discover the six main causes — from PAS100 standards to green-waste inputs and quality-control limits.

Most bagged “Multipurpose Composts” (MPC) are formulated growing media that give fast plant performance but are not humus. True compost (e.g., PAS100-certified green-waste compost) is biologically active and still decomposing; humus is the stable end-product that forms slowly in living soils.

No — they serve similar roles but are very different in composition, biology, and behaviour.

Small pieces of plastic can appear in compost due to green-waste recycling limits. Learn why it happens and what standards apply.

While retail MPCs are now very clean, small contaminants can still occur — usually due to:

• Legacy PAS100 composts (used in some bulk soil improvers or low-cost mixes). 
• Cross-contamination during handling or storage at depots. 
• Incomplete screening in digestate-derived materials. 
• Transport and packaging residues (fragments of plastic bale wrap or pallet film).

Manure and compost both feed the soil, but they’re not the same thing.

Manure is animal waste mixed with bedding such as straw or sawdust. Compost is organic matter that has been fully decomposed. Both improve soil, but manure must be composted before use.

No. Manure is animal waste mixed with bedding such as straw or sawdust. Compost is organic matter that has been fully decomposed. Both improve soil, but manure must be composted before use.