"Broadback" wrote in message
I am constructing a largish rose bed in my garden. I have marked
out
and am removing the turf, well more matted weeds really. The "soil"
beneath is very poor, consisting of clay and sand mixed with many
pebbles of various sizes, it is impossible to dig without loosening
with
a pickaxe. If I dig in plenty of horse manure would this suffice,

I did what you have described but I had to do it after the roses were
planted. Some twit had planted the roses then put down weed matting
and topped that with pine bark mulch. The soil under the weed mat was
like concrete and I'm astounded that any roses survived and they
looked very sick.

I dug in horse poop where I could and if too close to the roses, just
put it on top of the soil and then mulched over the horse poop with
lucerne hay. It worked, the roses now look healthy and the soil is
friable and getting to be a better colour with each year.