A springtime drive across Texas is a journey past roadsides and prairies crowned with blue. Between March and May, millions of Texas bluebonnets bloom in a sea of color that has earned them the title of Texas' state flower. The Texas bluebonnet, however, is just one of dozens of blue flowering plants that thrive throughout the Lone Star State. They range from modest prairie wildflowers to evergreen trees.
Perennial Carolina larkspur (Delphinium carolinianum) grows wild in the dry soil of Texas' brushlands and hills. Its 6-inch spikes of pale blue blooms appear on slender downy stems between April and July. Their spurred shape, according to the Lady Bird Johnson Wildflower Center, accounts for Carolina larkspur's Spanish name, "espuela del caballero." It translates as "the horseman's spur." Most effective when planted in groups, Carolina larkspur tolerates a range of soils from sand to clay. It performs best in partly shady locations with dry, sandy soil. Ingesting any part of this plant is potentially fatal to animals and people.
American wisteria (Wisteria frutescens) is a woody vine with deep-green glossy leaves. Reaching 30 to 40 feet, it has 6- to 9-inch cascading clusters of 1-inch blue-purple flowers in May and June. Texas' Dam B wisteria cultivar continues to bloom periodically over the summer and fall. Brown seedpods follow the flowers. The vine grows wild along Texas' riverbanks and in upland thickets. Plant it in moist, acidic sand, loam or clay. It does best in rich loam and a sunny spot with southern or southwestern exposure with wind protection. The Missouri Botanical Garden cautions that American wisteria may take longer than three years to flower. Early spring fertilizing and periodic pruning can stimulate blooms.
Texas Mountain Laurel
Texas mountain laurel (Sophora secundiflora) is an evergreen shrub or tree standing between 10 and 30 feet high. Most plants reach 10 to 15 feet. This member of the pea family grows wild in the rocky soil of central Texas' open plains. Its glossy dark-green leaves provide winter garden interest. In February and March, it has drooping 3- to 7-inch clusters of showy, fragrant lavender-blue blooms. The flowers' fragrance, says the Lady Bird Johnson Wildflower Center, compares to the smell of artificially flavored grape candy, gum or soda. Fuzzy gray seedpods with bright red, toxic seeds follow the flowers. Plant deer-resistant Texas mountain laurel in well-drained alkaline soil high in lime. Drainage is more important than soil type. Drought, heat and cold tolerant, it likes full sun to part shade.