Multipurpose Compost (MPC) is the familiar bag of “all‑round” growing medium found in every garden centre. It’s formulated to give quick, reliable results in pots, containers, hanging baskets, and raised beds. In this retail context the word “compost” doesn’t mean decomposed garden waste — it means a manufactured, ready‑to‑use planting medium designed for convenience.
What it’s made of
Visit Tony’s unique insight into MPC products in the Product Reviews section.
Modern MPCs are blends of organic fibres and controlled fertilisers. Most are now peat‑free or peat‑reduced, using combinations of wood fibre, bark fines, and coir. A short‑term fertiliser charge — usually lasting six to twelve weeks — feeds plants while the fibrous base holds moisture and air.
Each manufacturer adjusts the recipe for texture, water retention, and price, so no two suppliers are identical. To see how these ingredients vary, explore our What’s in the Bag section, where we compare leading approaches and explain how different base materials behave.
What it is not
Despite the name, MPC is not the same as homemade or PAS 100‑certified compost. These composts are ‘microbially active’ and primarily for soil improvement. MPC is produced to be clean, consistent, and microbially inactive — ideal for short‑term plant growth but not for building long‑term soil fertility.
As the base materials are still breaking down, the structure and nutrients naturally decline after a few months. That’s why planters filled only with MPC usually need regular feeding and periodic replacement.
Many gardeners also confuse MPC with specialist composts — the quick guide below helps set the record straight.
How it differs from other composts
| Compost Type | Key Difference from MPC |
|---|---|
| John Innes 1, 2 and 3 | Each JI product contains sterilised loam and sand in different proportions defined by use (seed, mature plants). |
| Seed Compost | Finer texture and lower nutrients to avoid seedling scorch. |
| Ericaceous Compost | Formulated for acid‑loving plants (azalea, blueberry); MPC is near‑neutral pH. |
| Home Compost / PAS 100 | Microbially active and nutrient‑cycling; improves soil but may be too coarse or variable for pots. |
See the full guides in our Compost Type FAQs to choose the right mix for your plants or soil.
Putting it in context
Think of MPC as a convenient, all‑purpose starting medium — perfect for containers and seasonal displays, less suited to permanent soil health. For gardeners who want to move beyond “one‑season compost” toward living, self‑sustaining soil, visit HealthySoil.co.uk for deep dives into compost fractions, biochar, and humus‑based systems that keep nutrients and carbon cycling year after year within the framework of The Callaghan Soil Management System.
Summary
Multipurpose Compost is the modern, packaged answer to easy planting: lightweight, clean, and consistent — but temporary by nature. Understanding what’s inside, and how it differs from true soil‑building composts, helps you use it where it excels and look elsewhere when you want lasting fertility.
Disclaimer.
Brand names such as Westland, SylvaGrow, RocketGro, Dalefoot, Carbon Gold, and others mentioned on this site are registered trademarks of their respective owners. MultipurposeCompost.co.uk includes these examples for informational and comparative purposes only and does not claim endorsement, affiliation, or suitability for any specific use. Gardeners and buyers should always check current product specifications and manufacturer guidance before purchase or application.
