Planting for height?
What can grow in narrow space 20 to 30 feet for privacy? Planter can be 20" depth max, but as high as possible and 4-5 feet wide or so (will probably have to make ourselves, or any recommendations where to buy?) We can't plant in the ground in this only-concrete area of the house... I am considering clump bamboo or cypress... ideally something that will be happy in a pot and grow tall and lean. Thx