Raised bed - are we doing it wrong?

MsCatFly · May 2021

Hello 👋🏻

We've dug up a lot of turf recently for a new bed, and we didn't want to waste it. We decided to build a new raised bed in behind an awkward area behind a wall. We just layered it up, and I thought the next stage was to put a layer of cardboard over it and wet it to suppress the weeds, give it a few months, then sow. I then saw articles online advising to build in layers if straw and cardboard. Do I have to take it all out and start over, or will a layer of cardboard on top do the job?

We just plan to plant a couple of hardy shrubs there. It's south west facing and we get the brunt of the Atlantic winds.

Thank you.

Obelixx · May 2021

Ideally, you need to stack the turves grass to grass and soil to soil with the upper layer soil upwards to stop the grass growing again. Done well it will break down to a good, crumbly soil ideal for planting.

Adding a layer or two of well-rotted manure and garden compost will also help with fertility and texture for the benefit of future plantings. Not convinced you need cardboard in this instance. That's more for making deep, no-dig beds on flat ground.

How are you planning to stop it all sliding down onto those aucubas?

MsCatFly · May 2021

Thanks @Obelixx. We're going to build a dry stone wall there. We've plenty of rocks. It will look informal, but sturdy.

If it were you, would you take them all up again to add the compost, or would it make do?

K67 · May 2021

You could probably get away turning over the edge turves and removing a couple of layers and restack as suggested but turf does take up to a year to breakdown so unlikely you would be able to permanent plant anything until next spring as the soil will sink quite a bit.
If you covered it with some top soil and multi purpose compost now you could put in some summer bedding plug plants.

Obelixx · May 2021

@K67 is right about how log it takes for turves to break down and that it will sink but you could re-stack the ones you have spreading them out along the entire raised bed and then, when your wall is built, topping it all off to a decent level with bought in topsoil and compost and then plant.

Have you any ide about what you want to plant there? Shrubs and spring bulbs are best planted in autumn so that gives you plenty of time to do the wall and move the turves about. If you're thinking more of herbaceous perennials you can leave the planting till spring.

Fire · May 2021

Does the area have somewhere to drain to? I don't the walls will like it much.

MsCatFly · May 2021

K67 said:

You could probably get away turning over the edge turves and removing a couple of layers and restack as suggested but turf does take up to a year to breakdown so unlikely you would be able to permanent plant anything until next spring as the soil will sink quite a bit.
If you covered it with some top soil and multi purpose compost now you could put in some summer bedding plug plants.

Yes, we're not in a huge hurry. We don't mind waiting a year for it to settle. We have so much else going on with the garden. We'll do that then, rearrange the top few layers. It's awkward to get into but it would be worth doing it right in the first place.

I might chance a few bedding plants, once we've sorted it out a bit, but they won't have any protection there, not sure how well they'd recover from the winds we get.

MsCatFly · May 2021

Obelixx said:

@K67 is right about how log it takes for turves to break down and that it will sink but you could re-stack the ones you have spreading them out along the entire raised bed and then, when your wall is built, topping it all off to a decent level with bought in topsoil and compost and then plant.

Have you any ide about what you want to plant there? Shrubs and spring bulbs are best planted in autumn so that gives you plenty of time to do the wall and move the turves about. If you're thinking more of herbaceous perennials you can leave the planting till spring.

I was thinking of some hardy shrubs. Even yesterday we had gale force winds! The sacrificial evergreen shrubs I just planted along the front wall were bending over backwards!
It would be lovely to plant some perennials and bulbs but they'd take a beating. That corner is the first glimpse you get of our house, so it would be lovely to have something colourful. I mentioned in another post asking for suggestions about what to do behind the wall, a tree was suggested which we still hope to plant. We thought an Amelanchier Rainbow Pillar just before the raised bed, we'll probably have to move a few aucubas. We can't get that variety of Amelanchier anywhere in Ireland though, so that's on hold.

I did face as many of the sods as I could grass to grass, soil to soil, but they're all uneven so it ends up like tetris and trying to keep the pile from falling. 😂

MsCatFly · May 2021

Fire said:

Does the area have somewhere to drain to? I don't the walls will like it much.

Not sure. I assume it would drain through the earth, no?

Obelixx · May 2021

It should but if the earth is really compacted it won't so best to try and break it up a bit if you can. Just stick in a garden fork and loosen it. No need to dig or excavate.

If your site is really windy I expect taller evergreens may suffer as even they will not like the desiccation caused by strong winds.

Have a look at forms of rock rose such as -
https://www.rhs.org.uk/Plants/79127/Helianthemum-Beech-Park-Red/Details
Hebes such as this one https://www.rhs.org.uk/Plants/124402/Hebe-Charming-White/Details or Celine or Champagne.

All are shrubs which will cope with full sun, good drainage and exposure to wind.

hogweed · May 2021

I would perhaps think about spreading out the turves to maybe the pillar so there is less pressure from the depth of soil pushing against these two walls. Then building the wee wall from the pillar across.

Raised bed - are we doing it wrong?

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