bush column columnar England english evergreen garden Great Britain hedge home house kent Penshurst Place plant shrub Taxus baccata topiary tree yew aerial-roots banyan banyan-tree columnar-tree competing competitive constricting distinctive epiphytes external ficus fig growing growth power powerful root-system Roots strangle strangler strangler-fig strangling strength strong sub-tropical trees tropical Australian-variety blue-sky columnar-shape conifer coniferous cupressus-sempervirens cypress dense driveway-planting elegant evergreen-conifer foliage golden-foliage narrow-space-growth natural nature ornamental-tree pencil-pine popular potable screening sky stately Swanes-golden-pencil-pine thin upright vigorous