The bluebonnet plant is a form of lupine they grows throughout the Southeast and South Central United States. Also known as buffalo clover or Texas lupine, bluebonnets can be found throughout the state of Texas and are, in fact, the official flower of the state. They are tough, drought-resistant plants that are commonly found in large numbers in fields and meadows and provide a dazzling display of bright blue flowers in the spring.
The term bluebonnet actually encompasses several different species of lupine that are indigenous to the United States. These include the Lupinus harvardii, also know as the Big Bend bluebonnet, Lupinus suvcarnosus, commonly referred to as the sandy land bluebonnet, Lupinus plattensis, found frequently in the Texas panhandle, and the tiny Lupinus concinnus, also known as the annual lupine, found in the Trans-Pecos area. The most widely recognized species is Lupinus texensis, the official Texas bluebonnet.
Bluebonnet is an annual, growing from 12 to 24 inches high and about 12 inches wide. The leaves grow on short stems that grow out from the base of the plant. Each leaf is compound, with five leaflets that radiate from the end of the stem. The leaflets are oval in shape, approximately 1 to 2 inches long and 1/4 to 1/2 inch wide. They are bright green, slightly fuzzy and often upwardly cupped. The roots of the plant run fairly deep for the size of the plant.
The flowers of the bluebonnet are the most recognizable portion of the plant. They form in dense clusters on a spike that grow from the center of the plant. Each flower resembles a pea blossom in shape. They are royal blue in color, with a white center and tiny yellow anthers. Occasionally, pink and white flowers will occur naturally. The terminal end of the flower cluster at the top of the spike is typically a small collection of white undeveloped flowers. Bluebonnet flowers bloom from March through May.
Bluebonnets are easy to grow from seed. They require full sun to grow well and also need well-drained soils that are relatively rich in organic material. They prefer gravelly soil and cannot tolerate wet or dense soil conditions. The best soil temperature for germination of seeds is between 55 and 70 degrees F. It is important not to overwater the seeds or the plants.
While the vast majority of bluebonnets grow wild in meadows and pasture lands and along roadsides and embankments, they can also be cultivated. Bluebonnets can be grown in raised flower beds or as container plants and make a welcome and colorful edition to regional gardens.