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

Large DIY wooden planters - plant recommendations and drainage/false bottom

medomagemedomage Posts: 22
edited September 2023 in Problem solving
I've made two large wooden planters out of gravel boards. Each are 150cm long and 40cm wide, and 60cm deep.

We had a surplus of top soil and compost to use (quickly), hence the build. I just need to line them with pond liner (with drainage holes).

However, I'm concerned about filling each completely with the soil-compost mix because of a) drainage, and b) weight.

Do I:

a) build a false bottom halfway up with more of the wood (although I'm worried it won't hold the weight); or

b) fill the bottom with something to help the drainage? (I've found some ideas online - e.g. packing peanuts, empty plastic bottles - but would need a lot so that's not an option. One idea online was to use a couple of large plastic collanders, or upturned buckets/pots with holes drilled in them.)

EDIT: Also, some recommendations for plants suitable for planters would be welcomed! in a sheltered north-facing position, so gets some sun in the afternoons. We have a couple of salvias I was going to put in them, but they seem happy in their pots and obs need v good drainage, so these might not be suitable.

Would welcome people's thoughts/experience.
«1

Posts

  • Busy-LizzieBusy-Lizzie Posts: 24,043
    Presumably you will make holes in the bottom for drainage?  What are you thinking of planting in it? If shrubs or roses then 60cm deep is good. If annual flowers or veg then you could put pieces of polystyrene in the bottom.
    Dordogne and Norfolk. Clay in Dordogne, sandy in Norfolk.
  • medomagemedomage Posts: 22
    edited September 2023
    Thanks for replying. Yes the bottom will have drainage holes. We're not 100% sure what we're planting in them, but it won't be a shrub or a rose. Recommendations are welcome! (We have a big pile of soil that needs moving, hence the planters and the rush. I have no polystyrene to put in the bottom sadly.)
  • medomagemedomage Posts: 22
    @Busy-Lizzie I've edited the post with extra info based on your comment, thank you. 
  • CrankyYankeeCrankyYankee Posts: 504
    I have several large planters and I like to use hugelkultur methods for these; branches and sticks at the bottom (softwoods are better than hardwoods), leaves and grass clippings over that, a layer of manure (if you're not going to plant until next year, fresh is fine), then soil.  As the lower layers compost they provide heat and moisture, but you will have to top up the soil layer annually.  I mostly use this for raised vegetable planters, but I've planted herbs and annuals in these planters and they've done great.  Due to our extremely cold winters, I don't use planters for perennial plants or shrubs.
    New England, USA
    Metacomet soil with hints of Woodbridge and Pillsbury
  • medomagemedomage Posts: 22
    @CrankyYankee Thanks for this! Do you think hardwood logs would work? We have a few of those.
  • CrankyYankeeCrankyYankee Posts: 504
    I generally use softwoods because they rot down faster, and I'm lucky that I have almost 8 acres of land with forest, so I scavenge for large pieces of log that have already begun decaying.
    This is a good guide to woods to use and avoid, and it does mention oak, apple, and maple are suitable for hugelkultur : https://wildyards.com/hugelkultur-wood-to-avoid/

    New England, USA
    Metacomet soil with hints of Woodbridge and Pillsbury
  • FairygirlFairygirl Posts: 55,117
    It largely depends on what you want to grow in them. There's no need for that depth of soil if you're just wanting annuals, veg or perennials, so you could probably fill it to around half way for most of those.  It's pretty deep even for shrubs, so you could add 6 to 9 inches of material in the base. I'm not sure why you're worried about the weight though - that would only matter if you were lifting them, which I'm assuming you wouldn't be.  :)
    You could certainly use anything you have for a layer on the bottom - cardboard and newspaper are good, especially if you don't have a compost bin for that. If you're wanting permanent planting in it, branches/stems, wood in general, would be better shredded, so that the drop in level that would occur when material is breaking down, won't affect the level at the top. For annual planting, that's less important because you would add more compost/soil every year. 
    Old pots, plastic milk cartons or anything similar, would also be fine, but it's worth adding a layer of something permeable over them to prevent too much of the growing medium falling through. If you have landscape fabric, or netting, or even old jumpers, that will do the job well. I do that with large containers if they're going to have planting which doesn't require huge depth  :)

    It also depends on your location and climate as to how you fill them - in cooler areas it won't dry out as quickly as it would in hot, dry ones, so that will affect your plant choices. If you have some idea of what you want to grow, it's easier to make suggestions. Some will need better drainage than others, but that's where containers can be easier to manage as you can tailor the medium to suit.  :)
    It's a place where beautiful isn't enough of a word....



    I live in west central Scotland - not where that photo is...
  • LeadFarmerLeadFarmer Posts: 1,500
    I made a similar planter out from tanalised timber so maybe consider some waterproof treatment for yours, especially on the inside. I also lined mine with plastic and put broken up pieces of polystyrene packaging in the bottom to act as drainage.
  • FairygirlFairygirl Posts: 55,117
    I believe @medomage is lining the timber with pond liner @LeadFarmer.  :)
    It seems to be open to the ground though, so not sure why drainage holes would be required in the lining. There's no need to have holes in the sides, if that's what is meant, and you wouldn't put any plastic on the bottom. 
    My raised beds are all lined, and open to the ground. Drainage is therefore not a problem in any way.  :)
    It's a place where beautiful isn't enough of a word....



    I live in west central Scotland - not where that photo is...
  • LeadFarmerLeadFarmer Posts: 1,500
    Fairygirl said:
    I believe @medomage is lining the timber with pond liner @LeadFarmer.  :)
    It seems to be open to the ground though, so not sure why drainage holes would be required in the lining. There's no need to have holes in the sides, if that's what is meant, and you wouldn't put any plastic on the bottom. 
    My raised beds are all lined, and open to the ground. Drainage is therefore not a problem in any way.  :)
    Understood.

    I put timber lats cross the bottom, with gaps, and lined with plastic along the sides and bottom, but punctured holes in the bottom to allow drainage. I was planting a climbing hydrangea which can be thirsty so wanted some water retention. 
Sign In or Register to comment.