uses of differing commercial composts

I think it's a case of just knowing the plants needs and preferences.

When in doubt, I either look up cultivation/care on the internet or get my books out.

Okay, here's the technical answer! John Innes contains loam, or soil, which multipurpose doesn't. JI No. 3 is for mature plants, No. 2 is for adult plants (not so mature) and No. 1 is for seedlings. The difference between them is the ratio of feed, etc., so if you planted seedlings in No. 3, the roots would be burnt. John Innes mixes are better for plants, but the mix is heavy, particularly once wet, so you wouldn't use it in pots which are on a roof, for instance. Hope that help.

I always use John Innes when the plant is going to be in a container for a while e.g my patio apple tree. For some reason the plants just seem to like it - i personally wouldnt use it as a soil conditioner say because of the price but use it for special plants!

I've got all-sorts in tubs and pots and I've never used John Innes for anything lol Like you, I find it all a bit confusing, so I just buy multi-purpose and that always seems to work fine for me.

im the same to be honest i use multi purpose.

blimey I didnt even realise there was different grades for John Innes, I use a multi purpose compost for everything. the one I use says it has John Innes in it but couldnt tell you which one.

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