Hello everyone.I'm new to gardening and am after some advice please.I'm planting a hedge row in the garden of my first home (using Leylandii) and am wondering a couple of things;1. What's the benefits of a 5ltr pot plant over a 2ltr pot plant?2. How far in from the pavement will I need to plant?3. How much 'footprint' will each plant take up when grown to about 200cm? I.e. what gap do I need in between each plant?I've researched for hours online but have found differing answers and am somewhat confused by it all.Many thanks in advance, any assistance would be gratefully received!Jack.