We’re planting an alder boundary behind a new beech & hornbeam hedge. The area is coastal & very windy & wet. How far apart do we space the bare root alder trees?
If the alder is to be a shelter belt, work out the number of plants at a spacing of 1.5 metres each way, dividing the spacing into the whole area. But plant at more random spacing, more or less, to give a more natural look.
Keep the trees back 3 metres or more from the hedge or they will over-shadow it.