The trees are pleached hornbeam. They are fast growing but we brought them in mature for instant impact - they are big plants which have been trained into form over a number of years. They only need to be clipped once a year and when placing you should leave enough room at the back so that you can clip the back side. Otherwise, as you say, the neighbours might object. Alternatively if you have friendly neighbours, I'm sure they would allow you to clip from their side.
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Indoor plants
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