There are few blues more intense and gorgeous than those found on annual lobelia. The mounding type, called edging lobelia, is beautiful for planting in rows in the front of beds and borders. The cascading type is stunning, like a sapphire waterfall, spilling from window boxes or pots.
Annual lobelia is in its glory during the cool weather of spring and fall. Except for cool-summer areas, such as the Pacific Northwest or higher altitudes, lobelia stops flowering during the heat of summer. Shear the plant back when this happens, and it will likely rebloom come fall.