raised bed for growing veg

Slaacer

Hi, I am in the process of building a raised bed to plant some veg. Since I have back problem I decided to build the bed on legs so to make it easier for my back. And as money is tight I am building it with left over plywood (18mm thick) for the walls and floor and builder scaffolding planks for the legs.

I am now looking to waterproofing the bed as the standard plywood is not gonna last very long without some protection. I've already drilled drainage holes but now I'm looking solutions to protect somehow the plywood from roting.

This bed is to grow vegetables so I have not used any paint or treated wood to avoid contaminating the soil and ultimately the vegs.

I have left over wide plastic sheet which I think should do the trick but then would the wood on the floor rot anyway with the drainage holes ???

Thanks for your ideas...

oats 2

maybe could last couple years.could be worth investing in waterproof plywood.

Slaacer

I agree though in this case I use whatever I had to minimise cost - but I will consider this when this one needs replacing...

goat2

oats 2 wrote: »

maybe could last couple years.could be worth investing in waterproof plywood.

i have never heard of waterproof ply, is it made of some plastics, does it last a lifetime, i am also interested in the raised beds for gardening,

if any one have ideas, please spill them

Currahee01

Marine Ply or WBP Plywood should do the trick.

I have 16 beds made from old scaffolding boards, no sign of any contamination...

Slaacer

I know the scaffolding planks are well weathered so shouldn't rot that easily. But i only had small ones which I used for the legs of my bed.

And unfortunately the plywood I used for the sides and floor is regular 18mm ply.
Hence why I need to waterproof it and I'm looking for a solution that will not contamine the soil and vegs.

Someone mentioned Linseed oil as a natural water repellant.

Where you live is really pretty Currahee01.
Do you mind me asking what you used to fill your raised beds?

Sonnenblumen

Slaacer wrote: »

Hi, I am in the process of building a raised bed to plant some veg. Since I have back problem I decided to build the bed on legs so to make it easier for my back. And as money is tight I am building it with left over plywood (18mm thick) for the walls and floor and builder scaffolding planks for the legs.

I am now looking to waterproofing the bed as the standard plywood is not gonna last very long without some protection. I've already drilled drainage holes but now I'm looking solutions to protect somehow the plywood from roting.

This bed is to grow vegetables so I have not used any paint or treated wood to avoid contaminating the soil and ultimately the vegs.

I have left over wide plastic sheet which I think should do the trick but then would the wood on the floor rot anyway with the drainage holes ???

Thanks for your ideas...

How do you propose to support the plywood and prevent it from sagging? Sorry but this is an exercise designed to fail.

You should be using Marine plywood and a permeable membrane and not PVC as the latter is more likely to accelerate the rot process.

Currahee01

Moonbaby wrote: »

Someone mentioned Linseed oil as a natural water repellant.

Where you live is really pretty Currahee01.
Do you mind me asking what you used to fill your raised beds?

We used Osmo UV oil on our cedar for the house, it might work as a water repllant on the ply but as Sonnenblumen said a permeable membrane may be the best option.

We filled the beds with the topsoil from the paths between the beds. We had more than enough and after a few trips to the garden centre we mixed in a bit of compost as well. I'm a complete rookie so its been all trial and error so far!!

fryup

Currahee01 wrote: »

Marine Ply or WBP Plywood should do the trick.

I have 16 beds made from old scaffolding boards, no sign of any contamination...

:)gorgeous absolutely gorgeous setting there, Currahee01

where is it? are you a commercial grower??

Currahee01

fryup wrote: »

:)gorgeous absolutely gorgeous setting there, Currahee01

where is it? are you a commercial grower??

Thanks fryup we're in Wexford (on the Blackstairs) it really does lift the mood on a good day

Its my first time growing anything so not quite at the commercial stage :P As I said before its all trial and error The raised beds just make it a little bit easier in terms of bending over and I really like the look of them!

oats 2

amazing garden well done

Micheal GIY

Currahee, that is a fantastic garden in a gorgeous setting. Its hard to believe that you are only starting out as you have done so much right. The beds look to be a good size and you have good access around them. On top of that you have put in a little plastic tunnel over one and have others covered with netting - you should be able to grow a great variety of crops there. Just one thing to watch out for - you say you are using soil from the site so just be sure to add some nutrients to the soil as you go along. This could be by way of digging in well rotted manure, or growing green manures in the Autumn then digging them into the beds in the spring, or leaving seaweed on the beds over the winter.

Slaacer, I'm afraid I have to agree with some of the later posters that this is not the ideal way to go about the beds. The same as yourself, I would always like to use what I have to hand, and even moreso these days, but a bed made from plywood up on legs could be wasted effort. Getting it to stay together will require some careful construction and reinforcing, while trying to stop it from rotting might be fruitless. Having said that, if you have managed to get it built, then make the most of it. Remember to put in good soil - a mixture of soil, peat (or substitute), and manure might be best. Also, as the beds are up off the ground, they may be more prone to drying out so just be sure to keep them watered when necessary. Good luck.

VirtualWorld

Personally I would've built the raised bed directly on the ground, filling the first foot or so with rubble or whatever you can get your hands on to bring it to your preferred height with the better soil/compost on the top. Sagging, then collapse seems to me to be a likely outcome with what you've described. It may not be too late to modify the current construction to suit this idea? If so, I'm all in favour of the giving it a go attitude and see what happens. It might be worth your while to head over to your local dump. Some of them have dumps of wood that can be picked from I believe... Nothing ventured nothing gained. Best of luck with it.

fodda

God i could just sit there all day and look at the view.:)

You cant always fill the raised beds up with stone(rubble) as some veg like parnips and carrots etc need deep fine soil.

Marine ply has waterproof glue i think so shouldnt seperate and should have a "BS" number on the edges........but it's very expensive.

sponge_bob

slaacer it might be worth your while investing in some scaffold planks, they can be bought pretty cheap these days 2-3euros each, a mate of mine sold 600 of them recently for 1.80ea. :eek: to a commercial buyer. so i wouldn't go giving anymore than a few euros each for them. i built 2 raised beds with them earlier this year usede 6 planks in ea. first off i used block for the legs and then laid 3 planks across them and stood the others on edge around them so i ended up with a box 8'x27"x9"deep. i lined the bottom and sides with old fertilizer bags so that the clay would hold the water a bit longer and help to keep the boards from being in constant contact with the damp clay. it worked very well the only thing was due to the bad summer and harsh exposed site i live on nothing grew properly in them.

littleredspot

If you're going to line it with plastic would it matter that the ply was treated?

Must agree that normal ply fails very fast untreated outside. If the budget could even stretch to WBP ply, it's not much dearer than regular and will last longer.

sponge_bob

i would not advise using ply as it will disintegrate very quickly, unless you are going to splashout and buy the good marine ply it would be a wate of time. also the bottom would need to be well supported if you are going to stand your bed up on some sort of legs as the weight of the soil and water will just cause the bottom of the box to sag and inevetibly burst. so i would suggest using at least 9x2 timbers to support the plywood bottom. in which case you may aswell have used scaffold planks to start with. i would also imagine that the sides would belly out as well if you were to use ply.

ply is a great material but it would not be at its best in this application, horses for courses and all that.