Adding some glamour to your garden, the Agapanthus Midnight Star (a.k.a. Agapanthus Navy Blue) has a dramatic roundel of showy funnel-shaped flowers in a very dark blue, on sturdy stems high above the narrow, lance-shaped leaves. It grows well in beds and borders, and particularly well in pots, as it benefits from constriction of the roots and good drainage.
The attractive seedheads of this summer-flowering evergreen perennial also provide autumn and winter interest. It can easily be progated by division.