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MPC compost with John Innes

DedekindDedekind Posts: 171
What is the typical usage of those Multi Purpose Compost with added John Innes? 

Can they be used for permanently planting in pots? (Of all sizes)


  • Pete.8Pete.8 Posts: 10,283
    I use it for seed sowing and potting on.
    It just has a bit more structure to it than ordinary MPC.
    I find it drains a bit easier yet still holds moisture - a bit like the fabled 'moist but well-drained soil' :)
    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • PianoplayerPianoplayer Posts: 624
    Hi - yes, I use JI no 3 mixed 50/50 with `ordinary` MPC when I am potting something that is going to live permanently in a pot. As Pete says, it holds more moisture and has better structure for things to live in for a longer period. Having 100% JI no 3 is too heavy, I find. The nutrients in it last for a few months, so you have to remember to feed after that!
  • DedekindDedekind Posts: 171
    But this is not the same as No3 with MPC I think its just "MPC with added John Innes" which probably means lots of different things?
  • PianoplayerPianoplayer Posts: 624
    In which case, sorry, I'll shut up.
  • DovefromaboveDovefromabove Posts: 83,863
    I think it might mean MPC with added JI fertiliser formulation ... but which number?  Does it say anything in the ‘small print’?

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.

  • Pete.8Pete.8 Posts: 10,283
    edited April 2021
    It looks like it has made up JI compost in it.
    So a mix of usual MPC and fine slightly sandy soil - something like 80/20.
    It's sold as seed and potting compost so it could be any of the JI fertilizer strengths.
    Either way it's worked really well for me over the last few years for seeds and potting on - I couldn't get it this year for some reason.
    this is the one I use when available
    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • edhelkaedhelka Posts: 2,322
    I used to use Westland MPC with added JI and liked it. It is a little bit more loam-based than usual MPC but not enough for permanent planting. For permanent planting, it would need more JI or topsoil added to it. I used it as normal MPC.
  • FireFire Posts: 17,116
    edited April 2021
    I have ordered some recently some Melcourt Sylvagrow Peat-Free Compost John Innes No.3  and it's great stuff. It's for a permanent planning of a shrub in a pot.
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