Texas Bluebonnets are annual wildflowers, with a one-year lifecycle. They typically grow in climates without winter freeze. Seeds are sown in fall, develop strong roots over the winter, and send up flower spikes of blue-violet topped with white in early spring - usually blooming March to May. After flowering is done, seed pods form.
However, there are some tricks to growing Texas Bluebonnets (Lupinus texensis) successfully - including planting in fall or scarifying seeds so that the tough outer coating breaks down before it can germinate. Read on to learn more about the needs of Texas Bluebonnet to make the growing process easier and more successful.
Texas Bluebonnet is an annual plant. It germinates, grows, flowers, and sets seed over the course of one year. If conditions are favorable in your garden, the plants will set seed and reproduce. It can take some time to establish a large stand of Texas Bluebonnets, as the seeds can be finicky with their specific requirements.
Light: Bluebonnets need a sunny position to do well. 8-10 hours of full sun is recommended. South or west-facing exposures offer the most sunlight.
Soil: Texas Bluebonnets can thrive in poor soil and disturbed soil. They can be sown in decomposed granite. They must have well-draining soil. Slightly alkaline soil is best. If planting in containers, good drainage is essential. Prepare your area before planting - Texas Bluebonnets do not like competition or being crowded by other plants. As with all wildflowers, seeds need good contact with the soil for best results with germination.
Spacing: If broadcasting seeds, clear the soil and roughen the area well. Plant 1 pound per 700 square feet (see coverage rate chart under "Plant Information" for Texas Bluebonnets). If planting individually, plant 2-3 seeds together with ten inches between the next planting, thinning to one strong plant after true leaves develop.
Planting Times: Texas Bluebonnet's hard seed coat makes it a great candidate for fall planting. Cooler weather and exposure to a few months of precipitation will help to naturally break down the outer casing of the seed. Transplants should also be planted in the late fall. Seeds are best planted in October or November. Early October gives them the most time to establish roots before winter.
If you're growing Texas Bluebonnets in a cooler climate with a winter freeze that would kill tender Bluebonnet seedlings, then it's best to plant seeds in the spring. Planting in spring will require cold stratification or scarification to break down the tough outer shell. See Germination Tips below!
There are a few tricks to ensure good germination when planting Texas Bluebonnet seeds.
Many wildflowers—including Texas Bluebonnets—have clever mechanisms in place that help protect them from germinating too early in the spring or too late in the summer. If you plant in fall, the seeds can follow the natural pace of the seasons, with cold and moist winter conditions breaking down the seed so it can germinate.
If you are planting in spring, you will need to cold stratify or scarify seeds to break down the tough outer coating before planting.
- If you're planning ahead, or planting a large amount of seeds, use the cold stratification method. This requires about 4-5 weeks of damp seed storage in the refrigerator. See our guide here: How To Cold Stratify Seeds For Spring Planting.
- For smaller plantings, you can scarify seeds, meaning scratching or breaking the surface of the seed and soaking them to break down the coating. See our guide here: How To Scarify Seeds For Spring Planting.
Small Spaces and Garden Beds: Plant shallowly (1/8 inch deep) and tamp down soil to make strong soil/seed contact.
Large Spaces and Meadows: Plant shallowly (1/8 inch deep) and tamp the soil down firmly by walking over it (either directly or with a board in between your feet and the earth) or by using a seed roller. Be sure to make strong soil/seed contact.