Around 50 hedgelayers took part in the competition at the prince's private residence on Saturday.
Charles, who is the society's patron, hosted the hedgelayers at a reception before handing out the awards.
The Prince spoke of his teenage "horror" at watching miles of hedgerows being dug up "in the name of agricultural progress".
"I don't need to tell you of the destruction that has been wrought over our hedgerows over the last 60 years," he told the assembled hedgelayers.
"As a teenager I watched in horror as miles and miles of such a wonderful part of the British landscape was grubbed up in the name of agricultural progress.
"Hedges which had stood for hundreds of years - even thousands - disappeared in an instant and now our hedgerows are under a new threat of disease with ash dieback threatening to destroy the vast majority."
He added that he hoped for "many more miles" of hedges to be planted as part of the Queen's Green Canopy campaign in the lead up to her Platinum jubilee.
The craft of maintaining hedges is often passed down through families for generations.
The hedges were laid out in a variety of styles - including Welsh Style, Midlands style, and the South of England style.
There are 11 styles of hedgelaying across the UK.
Phillip Powell, 24, who came first in the Welsh style, said: "I'm chuffed. It's a dying art so this is about preserving the rural craft.
"It's something my parents have done and will be passed down for generations."
He added: "It's really important. I started about 11 years old and I'll be doing it forever."
Hedges are an important part of the UK's ecosystem, offering homes to native birds and animals.
However, more than half of the UK's hedgerows have been lost since the end of World War Two.
Listen to ITV News' The Royal Rota: