I need something to screen off next door's garden. The fence between us belongs to her and is a very low picket fence. It's completely knackered but she's not likely to do anything about it anytime soon and I can't afford to offer to replace it for her. I thought I might grow something that would act as a natural screen - any ideas? Mustn't be as thick as a hedge because I have so little room. How about bamboo (too invasive?) or willow? Fence is South facing, soil is alkaline.
Really grateful for any ideas.