Red Arrows Culver's Root bears dense spikes of red buds which open from the top down into deep violet flowers from July to September on strong, upright stems. Smaller, branching lateral spikes create a candelabra-like effect when in full bloom. Red Arrows grows to about 4 feet tall and 3 feet wide and has lance-shaped leaves that surround the stems. Easy to grow, it prefers moderate to moist, well-drained soil in full sun. A good background plant in the perennial bed, it is attractive to butterflies.