Can anyone suggest any tall shrubs that would be happy in a long planter about 1m30 long, 50cm wide and 70cm deep? I'd like to be able to screen the view behind it if possible. A tree would also be nice but I'm not sure that the planter is really large enough?
We've got several photinias (Red Robin) in big tubs (half barrel size or slightly bigger) which we use as screening. Evergreen, and beautiful new foliage in Spring (lovely at the minute). We bought them at a decent size - about 1 metre tall - and paid about £30 for each one. You can buy smaller versions, but we didn't want to wait too long for them to reach a good size!
That's just what we've done - also got a couple at the side to screen us from our (lovely) neighbours. Photinias can be pruned to keep them under control (google for exactly when to do it), but may not need it if in a big tub. Scoop out the top layer of compost each year, throw away or put on a border, and replace with fresh compost. Feed occasionally. That's all we do, and they look great!