Forum home Plants
This Forum will close on Wednesday 27 March, 2024. Please refer to the announcement on the Discussions page for further detail.

Beginner - help with compost mix for containers

245

Posts

  • Jac19Jac19 Posts: 496
    edited September 2021
    I have a couple of Veronica Moody Blues and 4 Nepeta Catmints (Catnips). Very similar look.
    I prefer the Catnips.  A lot more flowers and more height, and a couple of months longer flowering season.
    I like to plant Black Adder Hyssops in between them for more height and more flowers.

    In fact, I might pull out and replace my 2 Veronicas at the end of the season because they have caught rust.  I will put in taller Black Adder Hyssops in their place.
  • Jac19Jac19 Posts: 496
    Fairygirl said:
    Grit is just bigger @susclarke  :)
    Grit sand is fine, but just be careful of the descriptions of sand in various places, because the labelling can be misleading, and the wrong type can make things worse re drainage  :)
    Yes- compost of any kind on it's own isn't any use long term  :)
    Probably wise re the Phalaris - until you see how it grows  ;)
    How much soil to compost ratio do you recommend in your experience please?
  • Hijacking the thread a bit.. when people say MPC only has nutrients for a few weeks, is that really the only reason why it's not suitable long term? I'd imagine anything you put in a container will eventually run out of nutrients by itself, unless you add some fertilizer yourself. Which you can do perfectly fine with MPC.
  • Another thing about MPC is that it breaks down into finer and finer particles quite quickly, and before long it’s almost dust … this means that it loses its moisture retentive properties, along with the aeration, and then roots become starved of moisture and oxygen. 


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





  • Jac19Jac19 Posts: 496
    MPC is a lot of peat and runs out of nutrients much faster.  Need soil in there.

    I would like to know what proportion of soil to MPC mix works well in the experience of people here please.

  • FireFire Posts: 19,096
    A lot of peat free MPC is available. A growth medium recipe depends what you are trying to grow, how and where.
  • DedekindDedekind Posts: 172
    edited September 2021
    Another thing about MPC is that it breaks down into finer and finer particles quite quickly, and before long it’s almost dust … this means that it loses its moisture retentive properties, along with the aeration, and then roots become starved of moisture and oxygen. 

    But then what is the point of mixing it with anything on a long term container
    ? (Not trying to start any kind of argument by the way, just trying to understand :) )
  • FireFire Posts: 19,096
    @Dedekind Something like a John Innes 3 recipe is designed for longer term planting - more loamy and more recommended. Peat-free versions are commercially available or you can make up your own.


  • Jac19Jac19 Posts: 496
    edited September 2021
    > But then what is the point of mixing it with anything on a long term container?

    Mix in a bit because it decomposes fast and gives the young plants fast nutrients.  They start flowering faster.  But put mostly soil in along with a slow-release fertilizer, and things will work well long term.
  • FairygirlFairygirl Posts: 55,117
    Not everything in a container will be a plant you want growing faster. If you have shrubs or trees for example, they need different care, and often a different growing medium from annuals, bulbs or perennials. 

    @Dedekind - the compost added to a loam based medium [the J. Innes that @Fire mentions ] helps to loosen it up as well as adding some short term nutrients. Using J.I alone wouldn't be suitable for some plants either, in the same way that compost alone wouldn't . You can add other things  -grit, composted bark etc to get the best mix for the plant you have. For the vast majority of containers, a nice friable mix which will drain well, but also retain some moisture, is the aim. Additional food depends on the plant  :)

    J.I. is merely a formula too, which is why there are different types. 
    It's a place where beautiful isn't enough of a word....



    I live in west central Scotland - not where that photo is...
Sign In or Register to comment.