Jose's Profile

I am a new 'gardener'.Since my retirement I have become increasingly interested in anything to do with growing plants.
I was born in Mauritius,and came to England in the early 60'and made it my home.
I have a garden,front and back of my home.I am fairly happy with the front,where I have some annuals and perenials .At the back,which is my WIFE's there are about the same as the front,and in addition there is a piece of ground,which she has ALLOWED me to grow some lettuces,pack choi,etc.I have been granted permission (by the g'vnor) to raise that particular bed.So my question is:How many litres of soil will I need to raise this 10x9 by ,say 6inches.
I would very much like to have anybody's opinion,please,thanks,joe