Bluebonnets, the state flowers of Texas, are blue flowers. Bluebonnets are able to survive very harsh conditions. While their hardiness might be helpful in your garden, you might be frustrated when only some of your bluebonnet seeds germinate. You might also plan your garden around a simultaneous explosion of bluebonnets only to find individual flowers emerging on different days within a 30 period.
Bluebonnets are winter annuals: They prefer to be planted in the soil in the fall and slowly grow throughout the winter, according to Texas A&M University. Bluebonnet seeds have a very hard coating, allowing them to survive in the soil for several years until conditions are right for the bluebonnet to grow, according to Son of the South, a Civil War and southern history website. The hard coating is an evolutionary advantage that allows bluebonnets to survive through harsh seasons. In fact, many bluebonnet seeds do not germinate even when conditions are right. The bluebonnets that do sprout will not always sprout at the same time; instead they sprout at different times over the course of about 30 days.
Despite their hard coatings, bluebonnets are susceptible to organisms that will attempt to consume them over the long period that they remain in the soil. The only way that you can get many bluebonnet seeds to germinate is through special chemical treatments that protect the bluebonnets from fungi and various other microorganisms that can kill them. Otherwise, you can purchase fully grown bluebonnets from a local nursery and plant them. Just don't plant their roots too deeply.
Bluebonnets thrive best when winter conditions are cold and wet. Throughout the winter, the bluebonnet slowly develops its root structure. The bluebonnet thrives usually when it is in well-drained soil. Bluebonnets cannot survive in clay soil and prefer sandy soil, according to Son of the South.
Bluebonnets grow throughout the winter, and winter rain will fuel the bluebonnet's growth, according to Son of the South. However, the drought-tolerant bluebonnets will die if you over-water them, according to Texas A&M University. As they emerge from the soil, the bluebonnets will need a lot of sunlight in order to grow adequately.
Bluebonnets fill whole fields with blue flowers, but they have plenty of predators. They are often fed on by animals, according to Son of the South; farmers often see their sheep and goats eating the bluebonnets. Pillbugs and soil fungi attack sprouting bluebonnets, too, according to Texas A&M University. Insecticides might be needed to protect the bluebonnets.