Raised beds a question

[altia13]

Hi I am new to growing things and I have decided to make some raised beds to gorw things. My question is: Is there a best depth for the beds to be?

altia

[tim_n]

Are the beds based on concrete, couchgrass or bare earth?

If concrete/couchgrass (ie where you're not planning to dig it over) you'll need about 2ft.

If you're digging over the land and want to just raise it, raise it to the level you're comfortable dealing with. Someone with a bad back may want it 3-4ft up, someone who's just looking at keeping it above a woodchipped path may only need a few inches.

Remember the taller you make it, the more soil you're going to need to fill it with. I used no dig beds which consisted of cardboard laid directly onto undug unweeded grass, followed by chicken manure, 1ft rotted manure and 1ft straw. That gave the plants something to root in and the straw stopped weeds from dropping down into the manure, so they just fried on the surface during the summer.

[altia13]

Thanks I am going to put the raised beds on grass with cardboard at the bottom. I am licky enough to be able to get as much horse manure as I want from my neddy in my user icon.

altia

[Annpan]

As deep as you like then.

Mine are 4inches 'deep' or rather... the boards are but I haven't had enough compost to fill all of them so I dig over the ground and plant in that. My potato beds got the benefit of the compost this year, so I have six beds that are 4 inches deep. and will soon have 18 that are just slightly above ground level, surrounded by boards.

Once you get over about a foot you have to start taking serious consideration of the strength of the retaining walls, you don't want it all collapsing on you.