I don't think the boards are made of wood. They look like recycled plastic to me. But, yes, the fence will rot and be pushed out and the beds would rot if they were wood. Also they seem to have heaped up soil around the tree trunk and have planted a Clematis armandii which would overwhelm the fence in no time. All in all this looks like a quick fix impractical design. The photo is in the UK so freezing soil isn't going to be a problem but even so I'd make the beds much less deep.

Cedar or pressure treated (pine) are more rot resistant types of wood and a nice coating of shellac or paint or to protect it from moisture. Plant roots would probably freeze and kill the plants if they weren't in the ground.

Mblant13–So, are you suggesting that the entire “box” would need to be filled with soil? We can’t get equipment into the back yard so that’s quite a workout of wheelbarrowing!!! Lol. Thanks for your response.

Floral_UK... what about the suggestion below to use pressure treated wood and then shellac? Or I know they have some type of paint that you use to paint your foundation To protect it from moisture.Perhaps I could paint the inside of the box with that? I assume there would have to be a side of the ‘box’ running along the fence as well so that might help a little, no? Thanks for your help!

I've never seen a raised bed made of any kind of boards which survived in good shape for more than a few years. I think the layout in the photo would be a mess within a couple of years, unless the bottom of the fence was raised on a concrete foundation above soil level and the bed sides were plastic, masonry or timbers, more akin to railway sleeper size. Add the freezing problem where you are and I think you need to rethink your idea. Does the bed really need to be that tall?

Hi Floral-UK. RE Your question as to whether the beds need to be this high—this my inspiration picture. Our deck comes to about 4 feet from the fence as this is the bylaw here in my community. So, I was thinking of building something like this from the deck to the fence. The difference—on our deck we are going to have furniture under a gazebo so perhaps we can just go with Cedars along the fence. Still, there will be something planted along the fence, at the very least meeting up to the height of the edge of the deck.

Pressure treated wood, protected by sealant, will last considerably longer than untreated wood but will still not last forever. The nature of anything organic is to rot. If you want invulnerable containers use plastic, concrete or stone. If you go with wood anyway, you can install vertical braces every 3-4 feet so to help with the weight of the soil pushing on the boards. Installing braces on the outside is better than on the inside but inside would probably still work. You could also install a thick plastic liner which should greatly increase the life of the wood, but plants will not survive without drainage so poke a few holes in the very bottom of the liner. If you choose to make the beds shallower for less labor in moving soil, be aware that shallow root space will influence the type and size of plants you can have, and increase the risk of winter damage from freezing. If it were me, I would put in the labor and have beds deep enough to insulate your roots considering you are talking about being in Canada. If you really only want the plants at the level of your deck, I would suggest installing your bed even with the deck even if you have to dig a couple inches to get good footing; that would involve less materials and greater insulation as it would be close to the ground.

If it were me I would consider installing shallower beds, made of an ornamental brick that matched your wood, going up just a few inches higher than the deck. No rot issues, better cold insulation, and still stylish. Plus if you don't install any bottom liner and it is close to the ground, you can plant anything you want (if you are just considering root space) because the roots will transition from your bed to the ground.

Yes, Lilyd74....I’m thinking I may have to go with shorter beds. As you suggest, the height of the deck. Perhaps I will just put Cedars along to hide that ugly fence that we have. Something like this perhaps?

I have tried repeatedly to add to this thread with the inclusion of 3 pictures. No go.

I'll try separate posting with individual pictures, what a pain...

Pieter

Wood, even this PT hemlock, will rot. This was after about 15 years.

Next posting

We decided to replace the 4x6 PT with a combination of concrete blocks we saw @ Lowe's and a combination of 2x4, 2x6 and 2x8 lumber and then line the structure with polyethylene such as you find in tarps for example. You can see that at the back of the boxes. The front of the boxes were topped with lumber to protect the front poly from UV exposure, the back will not see any direct light and will get shaded by the pots we place underneath, I'll show that in the next post.

Pieter

Thanks for your efforts with the pics, Pieter! I did not know you can plant perennials like that in pots! They look great. Do you have to bring them inside in the winter? (I’m a real gardening newbie!)

No, I don't bring them inside over winter, but I do keep them sheltered to keep them from getting root/crown rot from sitting in soggy medium.

Pieter