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Multipurpose and all-purpose compost – spot the difference

Is there a difference between ‘multipurpose’ and ‘all-purpose’ compost? Surely there must be, or why have two different types advertised?

Here in the Which? Gardening team the general consensus is that, as their names suggest, multipurpose should be fit for a variety of tasks, whereas all-purpose is fit for everything.

When we polled Which? Gardening members, two-thirds believed all-purpose to be fit for everything: seeds, young plants, container plants and cuttings. However, findings also showed that multipurpose compost is expected do all these things as well. To clear up the matter, we decided to investigate.

What did we find?

Fundamentally, we found that all-purpose doesn’t always mean ‘all’. When we checked the packaging of the composts we were testing for this year’s compost trial, we found that some that are labelled as all-purpose don’t recommend you use them for seeds, especially small ones.

So we approached manufacturers to flag our findings and clear up the confusion. However, we’re not certain that the responses received really settle the compost conundrum…

Richard Gianfrancesco from Westland Horticulture, makers of J Arthur Bower’s and New Horizon composts, told us that while multipurpose is generally accepted as being for everything, from seed-sowing to tubs and baskets, it’s best to check the packaging to see if it’s right for your tasks.

Andy Chalmers, managing director of Melcourt, which produces SylvaGrow, told us that all-purpose means that it is truly appropriate for most typical garden usage.

David Coop, head of technical development at Westland, which also makes Gro-Sure composts, said that research shows the term ‘multipurpose’ is familiar to more experienced gardeners, while newcomers are more familiar with the term ‘all-purpose’.

To add to the confusion, Gro-Sure Peat Free All-Purpose Compost with Four-month Feed doesn’t mention sowing seeds on the list of uses, although Westland tell us it can be used for that purpose.

Time to end the confusion

Just like using old compost won’t do your garden any favours, there’s also little to gain from using the wrong one either. But, how are we meant to know which one to use?

We think that better labelling is needed so that you don’t have to carefully examine the small print or try to second-guess if you’re grabbing the correct compost.

What do you think ‘multi-purpose’ and ‘all-purpose’ means, or should mean for that matter? Do you agree that compost labels should be made clearer so that you know what you’re buying?

Comments
Profile photo of Patrick Taylor
Member

Multi-purpose means that it can be used optimally for a range of different uses. This range will be specified on the packaging.

All-purpose should mean it can be used pretty much anywhere and for anything. It does I suspect carry warnings on certain plants sees that might be adversely affected/ not flourish such as heathers.

Profile photo of malcolm r
Member

dieseltaylor. Agreed. As long as the compost lists it’s applications (or unsuitability) on the pack. Ericaceous would not usually be an application for an all-purpose compost. But I think it would be better to give a compost that can do many jobs – seeds, cuttings, mature plants – the description “multipurpose” and give other composts specific descriptions such as “JI Seed”. “Ericaceous”, “Baskets and tubs”.

I don’t think composts could really be described as “all purpose” when plants have different nutrient requirements but for many people who will only buy one or two bags a compromise compost like this is adequate.

If in doubt, ask staff or read the pack.

Profile photo of alfa
Member

Packs need universal icon labelling to easily identify what they are suitable for.
i.e.
⚽ 🌱 🌿 🍜 🏨 🌴 🏡 E PF

which would be seeds, seedlings, potting on, pots and tubs, bedding, larger plants, houseplants, ericaceous, peat free.

List out all the icons then put a red cross through the unsuitable ones.

Profile photo of malcolm r
Member

Good idea Alfa but the problem is remembering all the icons on something you may buy once a year. On compost the pack is large enough to spell out the uses (and unsuitability).

Hanging basket compost is supposed to contain moisture retaining gel but I’ve never been confident that it is much use in a relatively small container. Does anyone have good reports? I set up a cheap drip watering system (£6.95 off Amazon) controlled by an old Hozelock battery-powered timer. Just comes on once a day but has kept the hanging gardens of mrs r going all through the summer.

Profile photo of wavechange
Member

I like the emojis, Alfa, but I don’t understand the choice of a football ⚽ to show that a compost is suitable for seeds.

Profile photo of alfa
Member

Malcolm, you just need a sign up over the compost selling area with all the icons and maybe a short explanation underneath, then just look for the icon you want.

Wavechange, a football was the closest emoji I could find to emulate seeds so you have to use your imagination.

I was going to edit my post and change the bowl of rice for a better looking pot but they all disappeared so I cancelled edit. The emojis look ok when you first write them but change when you submit the post.

Profile photo of wavechange
Member

Hang on Alfa. We have seeds in tennis, not football. 🎾

Profile photo of Patrick Taylor
Member

I like the idea alfa.

In fact the whole arena is complex as we have wool based compost, stuff derived from all manner of basic ingredients. However for the vast majority I suspect they only buy three types in any one year.

And then we can get to the mulches for even more choices!!

Member
Anthony Foster says:
18 June 2016

An icon system prominently displayed would assist in simplifying things.
There could still be a more detailed written explanation of the contents as is now provided by manufacturers.

Profile photo of malcolm r
Member

Professional growers will use the right composts. Perhaps Which? could find out what they are and where to source them.