Raised Bed - Soil/Compost Life.

[burnie]

My raised beds are on soil, but with a double layer of membrane to restrict weeds growing up(after 3 years it's still doing it's job I checked), so I only grow in around a foot of soil which is slowly getting deeper each year as I add compost or manure. You can for example grow stump rooted carrots especially developed for shallow soil, I actually grew some parsnips that hit the membrane, turned through 90 degrees and carried on growing, we had "L" shaped vegetables for dinner.

[rary]

My main raised bed sits on a concrete base and is 30 inches deep and from late autumn I start to fill it up with seaweed, I have found that the level drops quite a bit over the year, any bulky material like manure, compost etc. will also settle down, when you make the frame for your raised bed cover the soil with layers of cardboard then start to fill the bed, I would suggest that you start with compostable material (even if it hasn't started to rot) and again cover with cardboard or layers of newspaper,then top up with soil/compost, after growing in it if required you could always raise the sides a bit, though after a season the worms should have opened up the base layer

[Dynamite]

Will one foot deep be enough to grow in?

Have a look at the depth of mine in my gallery. I top up once a year with spent compost , manure(small amount) and home made compost. Usually ok.

Kind Regards.............Rob