Galveston County Master Gardener
Class of 2000
We all enjoy the state flower of Texas blooming the spring. It is a wildflower that germinates in the fall, develops a massive root system throughout the winter with inconspicuous tops, and produces the vibrant color in April and May.
The first requirement for bluebonnets is a minimum of 8 hours of direct sunlight. Next you need well drained soil which may mean building a raised bed (6 inches or more) and adding 3 or 3 inches of organic matter. Use scarified (chemically treated) seeds to ensure success. Only 20% of non-scarified seeds germinate. Seedlings will need to be protected from pillbugs by placing bait around the plants weekly during the first month after planting. Also, too much water can kill the plants. Bluebonnets are very drought tolerant.
To avoid germination problems transplants may also be used. With older plants handling and spacing are easier. They also reduce the chances of damping-off, a fungal disease that causes stem rotting. But be careful not to plant them too deep. The sooner in the fall (beginning in September) the seeds and transplants are planted the larger the blooms and plants will be in the spring.
To keep bluebonnets blooming longer, remove old blooms. This will encourage side shoots as well as delay the seed production which stops the blooming.
If a lawn display of bluebonnets is desired, you will need bermuda grass or zoysia grass. St. Augustine lawns do not go dormant early enough in the fall and grow back too early in the spring. Aerate your lawn no later than Thanksgiving with a plug type aerator. Sow the scarified seeds and rake with a lawn broom to insure some of the seeds end up in the aerator holes. Water your lawn thoroughly. Competing winter seeds can be controlled with Ortho Grass-B-Gon without harming the bluebonnet plants. After the blooming is over, you can wait until the plants go to seed in June or you can remove the plants right away and replant in the fall.