That shop-bought hedging looks good, but I won't have enough for the length needed and I'm not sure I can get any more so I'm trying to make something similar for myself. Here's how I'm doing it:
Start with Graham Avis textured mat and Continental Models "seamoss"
Cut the mat into thin strips and the seamoss into small branches
Lay the branches in a hedge-type shape
Soak the strips in dilute PVA glue and lay them over the branches
Fill in the gaps with various textured foams - I'm using Green Scene "Bramble", "Oak Leaf" and "Elm" and Village Models "Conifer".
I hope this suggests the slight colour variations seen in most wild hedges
