How to fill a very deep raised bed

[Rantypanties]

Hello, I’m hoping for some advice about our very tall raised bed! It’s incorporated into a wall that’s just about a metre tall.

It isnt enclosed so there is still access to deeper soil. I’ve read online to perhaps put logs in the bottom before a sand/soil mixture then soil for the plants but my husband isn’t convinced and reckons it just needs big rocks at the bottom!

I’d appreciate any advice you can give me, thank you!

What are you planning on growing in it???

If its part of a retaining wall, with very shallow shrubs/flowers on top, then rocks seems fine at the bottom with soil on top. If you actually plan to grow anything like vegetables, larger shrubs/plants that you care about etc then I have no idea why you'd fill the bottom with rocks? 1m isn't that high for raised bed!

I'm far from any expert BTW- just trying to work out my own raised beds currently, so reading up alot.

I'd just put soil. Putting logs mixed with manure is just a way of creating soil which may work out cheaper if you have good access to those things.

It’s part of a wall with a pergola so I’m hoping to plant grape vines or wisteria however it’s not very wide so unsure if that would have an impact on the plants’ growth?!

I’m a complete novice, the builders built it up and I thought ooo a place to have some climbers…but didn’t give it any practical thoughts at all! I’d probably just plonk some nice smelling plants/ornamental grasses on top to hide the fence behind the wall!

I guess the rock idea is for better drainage? The ground underneath is the worst kinda clay so it’ll be a miracle if anything nice grows in it elsewhere in the garden tbh.

With the energy crisis I did think logs would be better used for heating our house!!!

Buy a bale of hay or straw to fill the bottom, layer of newspaper and cardboard, twigs etc and then just use compost for the top 12-15 inches. This is what we did with our deep raised beds. Cheaper than logs!

Thank you @Didicat ive just been looking up bulk buying soil and I like your suggestion a lot more!!

Wouldn’t the logs/ straw and paper degrade and lose volume?

then the level of soil your plants are in would reduce and could leave roots exposed

Styrofoam blocks.

My raised beds (they're VERY raised!) have an entire smashed up bathroom suite in them.

Probably not very cost effective to rip out your bathroom suite to fill up your planters... but if you have a spare one hanging around, it works really well 😂

We filled ours with fresh manure from a local stables, a bale of straw, cardboard on top and then a mix of topsoil and compost.
The stables gave us the manure free but we had to collect it ourselves.
Ours is used to grow vegetables.

🤣🤣

I think it would be better to put in stuff that will rot down and become part of the soil, rather than rocks or polystyrene.

We had some work done on our garden last year so I have just filled a big raised bed with woodchip and small branches and twigs from that, some old grass clippings, some chicken shed waste from friends who have chickens and compost from the big bag I had delivered last month.

The basic point is to put anything you have lying around to do the bulk if they are very tall, then some good soil on top, for cost effectiveness.

If what you put in is organic, it will break down and eventually make good soil (faster and better if you add some source of nitrogen, like horse manure or in worst case fertilizer), however it does mean it will settle and sink, at which point you'll have to top it up some more.

Just soil will sink too. Bathroom suites probably won't, if they're sufficiently smashed up.