Verbena (Vervain) White Flower Beds Potted Plants Plant Mature Height: 12 - 16" Annual ornamental plants Drought-resistant, tolerating full to partial sun, and enjoy well-drained, average soils Attracting Lepidoptera such as the Hummingbird hawk-moth, Chocolate albatross, or the Pipevine swallowtail, and also hummingbirds.