Mulch from evergreen trees on beds?

I’ve had a tree surgeon chop down 17 old evergreen trees at the back of my garden which had grown huge but scraggy. He shredded all the lighter branches and now I have 3 mountains of ‘mulch’ – how long should I wait before using it under trees, shrubs and (newish) hedging? One ‘mountain’ is touching the lovely beech hedge, am I right in assuming I should move that?