Rick B wrote:
Any ideas would be most welcome.

We have similar raised garden beds, but not as large because I would
have to walk all over them if they were any larger.

I would just go with good quality loam. You probably won't save that
much anyway.

And it is all going to sink and settle and that poor quality crap goes
rock hard.

I'm a comfrey planter to help convert poor soil to good soil, but it
does take time and some people have trouble getting rid of it again.


We lined our beds with heavy layers of newspaper, which lasted for about
24 months, then the kikuyu breached it, but a paint with roundup fixes
that. I don't want the chemicals, but I'm not in a mood to continually
weed it out. The latest one we lined with piles of black plastic
(because we had it). So far so good (12 months).


Have you considered getting a truck load of river sand and hiring a
rotary hoe for your heavy clay. Especially if you are going to produce
great piles of compost. Actually, just rotary hoe in anything organic
you can lay your hands on rather than going through the labour of
composting.