When we first received 'Princess Diana' clematis in the nursery, there was no sign of blooms, yet a month later, deep pink, tulip-shaped flowers were attracting the attention of the staff as well as pollinators (check out the picture of the dragonfly resting on the flower!). Clematis grows so quickly, it can reach its maximum size of six to eight feet tall in no time. Support is required so provide a trellis, arbor, fence or obelisk that the vines can cling to. Keep its roots protected from the sun by planting small shrubs, perennials, or annuals at the base, and make sure the top is in full sun for best blooms.