Hi - Mrs Spratt... If you have neighbours who have gardens they could perhaps let their hedge grow a bit longer than usual to let you then take cuttings.
It all depends on how close you are to the Sea, as to how long it would take your Hedge to take root if you are a fair way from the sea, then their should be no problem
But if you are close to the Sea, its better to get cuttings from one of your Neighbours, because these cutting will be well used to the salt in your soil witch should diminish as the years go buy, but that said if its cuttings you are using then its better to use a spade and to force your spade into the soil to the depth of the spit of your spade, whilst waggling your spade put your cutting in then give it plenty of welly this should force out any trapped air.
Now once you get your cutting in if this is what your using it may take your cuttings three good years before they get established in-to your soil, they will grow but it will be slow growth.
If you getting your Private, or Hawthorn, from a Gardening Centre they should give you a little advice on how to bring your young plants on, as in feeding instructions take all advice offered.
Their are several ways to lay out your hedge, before planting it for quick results you could put in two rows of Private, but stagger the plants like one and one and where the and is above you put one of your cuttings in the other row should have a plant at each one of the one's above here and you need at least two half feet between the two Row's for best results.
If you have any problems understanding whats above maybe the best way i could explain it to you would be to send you an E-Mail...
All the very best of luck top you...
And the laying of your Hedge.
High - Ruchill