Evergreen screen in a tub
I want something to grow in a large tub or tubs to hide a heating-oil tank, which is just over 5 feet tall. The strip of concrete that it will be standing on is just over a foot deep and 8 feet across. We had trellis with the tank that we are replacing, and I don't want it again. I was thinking about an evergreen grass or bamboo, but I've looked at loads and they either need cutting down in late winter, or need shelter, or are quite short. The site is exposed and south west facing. I would welcome suggestions apart from grasses as well. Any thoughts?