Well you can buy galvanised steel garden bed frames for a few different depths, I think I've seen them Bunnings and certainly at most large plant nurseries.

Good luck
Bill

yes corrugated iron beds they come pre-made(not cheap0 or get some iron from the scrap yard.

len

Here is a link that might be useful: lens bale garden

Thanks Guys, hmmm i do like the look of the "steel", however i am worried about the top wouldn't it be sharp?

Thanks S.

Hi Sal,

i was having the same queries when i was looking at making some raised vegie patches of my own. i was worried about having steel since i have small children. however a friend of mine put me on to a really safe steel edge! its amazing we have had it for a few months and i love it. NO SHARP TOP! we got the rusty looking one but they do have Galvanized as well. :)

Here is a link that might be useful: FormBoss Metal Garden Edging

It really does come down to
(1) intended use
(2) cost
(3) looks
and whether you want to remove it and whether you or anyone else in the family is "handy".
Those steel ones would probably last a long time but they are expensive. Still, they are light enough to move if you have to.
Timber can be found in off-cuts but needs someone to saw and bolt into place. And some folk don't like treated timbers for vegetables.
Bricks work as long as they are aged, but not at the height you mentioned unless re-inforced, which means cementing together which means maybe lime leaching into the soil.

400 mil, look I'd be considering old railway sleepers, they're still available: that old hardwood will last for many years in the garden and, in my experience, they've no leaching chemicals to contaminate the soil.

B.

bit late but better late than never. never be over critical if something doesn't appeal so be it, but never close doors.

for those who suffer old age issues these beds are ideal, the edges are sharp but will only cut if you slide along them we have had not a single injury, the star pickets are above head high for the majority.

simple philosophy use what's available.

Here is a link that might be useful: lens garden page