Burton - There is a huge variety of hedging plants in the UK. Hazel, blackthorn, hawthorn, holly,
ash etc...
You describe bending branches down to force them to
root - which is definitely used when trying to encourage gaps to fill - but for the most part the bent branches just continue to grow in their new position, sending up vertical shoots. The weaving process, followed by the regrowth, makes for a dense stock proof barrier right down to ground level.