Forum home Garden design

Galvanised metal planters

LoxleyLoxley NottinghamPosts: 4,973
Do people insulate their metal planters? 

I've got a 2x2x3ft galv. water tank I'm planning to put a young cherry tree in. It will get full sun until 2-3pm.


  • Lizzie27Lizzie27 SomersetPosts: 10,503
    I haven't with two of mine because I didn't know you were supposed to but I understand you use bubblewrap on the inside. I'd have thought if anything that would make the soil hotter, not insulate it against heat. Perhaps others can explain the science behind it. 
  • LoxleyLoxley NottinghamPosts: 4,973
    I guess it's like how a thermos can keep liquids cold as well as hot. I might try and get hold of some polystyrene sheets to line it. The tank has a lip so it would also help when it comes to removing the root ball if/when I need to put it in a larger container or the ground. 
  • Lizzie27Lizzie27 SomersetPosts: 10,503
    That might work quite well. 
  • ObelixxObelixx Vendée, Western FrancePosts: 28,555
    Roots enjoy neither being cooked nor frozen.   Insulation also helps prevent serious frost damage to roots in winter.  Worth doing in a big metal pot that you can't move to shelter.  If it's too late and already planted up, think about wrapping bubble wrap round the outside for winter.
    "We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw
  • LoxleyLoxley NottinghamPosts: 4,973
    Not planted yet. Was going to put it in the container on the right, but after messing about with them have decided to put it in the big one. Will dig out some polystyrene sheets to line it. 

    I'm also half filling the container with a layer of gravel then a layer of sharp sand before adding soil.

  • LoxleyLoxley NottinghamPosts: 4,973

    I used plastic storage box lids to create an inner wall for insulation. For drainage I filled the base with upturned plant pots and covered with gravel, and then geotextile fleece. To fill it up I used a couple more bags of gravel, and several bags of sharp sand mixed with some topsoil. Then finally about 40cm depth of just topsoil. It took a lot to fill!


  • Lizzie27Lizzie27 SomersetPosts: 10,503
    Gosh, hope you enjoy the fruits of your labours!
  • Hostafan1Hostafan1 Posts: 33,305
    " during the rainy season."
    This is the UK, every season is the rainy season.
  • LatimerLatimer Latimer, BuckinghamshirePosts: 790
    Morning @Loxley. I’m about to do the same with a galvanised planter (different plants though!) Do you not need any compost mixed in there with the top soil?
  • FairygirlFairygirl west central ScotlandPosts: 49,019
    As it was a tree being planted, mainly soil is needed @Latimer. Compost breaks down, and eventually means more topping up. Soil doesn't settle quite so much, but still needs refreshing each year, especially with a productive tree. 
    I don't think I'd have used sand though. I'd just have used grit or fine gravel mixed with the topsoil, but perhaps @Loxley could let us know it went  :)
    It's a place where beautiful isn't enough of a word....

Sign In or Register to comment.