Garlic

Looking through my various collection of grow your own/allotment type reference books , these are my findings on depths to plant garlic-

John Harrison- 2" deep
Dr D.G.Hessayon 2" deep
Andi Clevely 2"- 4" deep (deeper for light soil)
R.H.S  1"deep
Susan Berger 30cm deep (thats just over an 1")
Caroline foley 3"- 4" deep
Carol klein 1" deep
 

I planted mine at 2" depth  as it seems to be a happy medium.