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When growing veg in pots, what's the best soil to use?

gilla.walmsleygilla.walmsley Posts: 312
edited February 2022 in Fruit & veg
After the installation of my greenhouse last month I'm going to have my first proper season of growing veg! I have a small veg patch outside but have also bought some of the Haxnicks Vigoroot planters to grow some things inside the greenhouse (peppers, chillis, cucumber etc). I wondered what's the best soil to use - compost? Top soil? Mushroom compost? A mixture? I live near a decent supplier of all so have the choice, but I'm never really sure what the best thing to use is!


  • You might be interested in Square Foot Gardening, in Mel Bartholomew's book he suggests 1/3 peat (I'm using coir), 1/3 vermiculite, and 1/3  commercial compost (made up of a mixture of 5 different brands).  This is my first year of having a 'go', therefore you might like to do your own research  :)  Just throwing in....
    Trying to be the person my dog thinks I am! 

    Cambridgeshire/Norfolk border.
  • FairygirlFairygirl Posts: 54,358
    It depends on what veg.
    Many things will grow in almost any soil mix, although things like carrots need poor soil. However, if it's specifically for those chillies etc, just something free draining - compost with some grit or perlite. You'll have to go through the usual procedure of sowing and potting on  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • Thank you Fairy girl! That's also good to know about carrots as I'm planning to grow those too...... though I never really understand how you can go about obtaining poor soil (especially when you live in a clay area!)
  • Yes "straight " topsoil will end up too compacted in a pot because of the watering required.  I would do a blend of soil and compost, depending on what you are growing.  Tomatoes   chillies,  cucumber etc, can use a good mpc, with grit or perlite to keep it open. 

    AB Still learning

  • Pete.8Pete.8 Posts: 11,143
    edited February 2022
    I grow cucumber, chilli and peppers in pots in my greenhouse.
    I use a mix of about 50/50 multi purpose compost and rotted manure. I add a few handfuls of perlite if it needs opening up a bit.
    Cucumber goes in a 22L pot, peppers in 10L pots and chillies in 5L or 7L pots

    PS - I grew some great carrots a few years ago in pots.
    I had some deep plastic pots, some spare MPC and some seed.
    I used only MPC and grew some amazing carrots. 
    The pot was kept outside.

    Billericay - Essex

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • This is all fantastic advice, thank you. I've noticed the compacted thing with top soil I've used in pots with flowers in, I wondered if I had done the wrong thing.

    I successfully managed to grow cucumbers and courgettes outside last year for my first ever veg growing attempt, but am completely clueless about most of it (I have however completely been bitten by the bug).

    Pete those pot sizes are super helpful thank you, as that's another thing I wasn't sure on!

    I'll go for a mix of mpc, a bit of manure and some grit then.

    Interesting on the carrots! I do have a section of soil in my garden that has low fertility soil in it (bought when I was doing a wildflower bed) so I could transplant some of that and use it mixed with a bit of mpc and see how I get on.
  • FairygirlFairygirl Posts: 54,358
    Old compost is fine for carrots, you don't need soil, as such. If you've grown annuals or anything in pots the year before for example, although, like @Pete.8, I've also grown them in just MPC. They just don't like too rich a soil  :)
    Pots are also good to help avoid carrot fly. Either that, or a physical barrier of some kind round them. They don't fly above about 18 inches to 2 feet.  :)
    I might grow some again this year, although with the amount of them I eat,  I'd need to turn the entire garden over to carrot production  :)
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • Ha I'm a bit like that with courgettes although even I could barely keep up with the volume of courgettes I got last year from just two plants! I was amazed. I've been gardening for years but had never been "into" veg... I had totally underestimated the joy it brings to be able to go into your own garden and pick something for your dinner  :)
  • FairygirlFairygirl Posts: 54,358
    Ah yes - the courgette problem....
    I remember my sister growing them in her first house when she came back up here. She ran out of ideas of how to use them. They were sick to death of the things after a few months  :D
    It's a place where beautiful isn't enough of a word....

    I live in west central Scotland - not where that photo is...
  • I also tend to use a rough 50/50 mix of compost/rotten manure with a handful of so of vermiculite. For carrots in pots I use the previous years spent compost from my flowerpots.
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