How To Grow Texas Bluebonnets

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.

Growth Habit: When planted in warm climates without winter freeze, Texas Bluebonnets germinate in late fall and create a low-growing rosette of foliage that will overwinter, sometimes reddening after the first frost. In early spring it will expand to 12-18 inches, sending flower spikes just above the foliage. After flowering, the plant will set seed pods and die back to the ground.

Thinning: In the early spring, as plants are starting to grow strongly, give them a little help by making sure they are not overcrowded, thinning plants to 10-12”.

Staking: No staking required.

Watering: Bluebonnet is a terrific choice for low rainfall areas as it benefits from underwatering. Too much water will decrease the gardener’s chances of success. Water when planting and sporadically thereafter, allowing natural fall and spring rains to do the job for you.

Deadheading/Trimming, or Pruning: Deadheading blooms can encourage side blooms to develop off the main flower stalk; this would be more practical in a container or small raised bed than in a meadow setting. If you plan to mow your meadow, do not mow until after seed pods are set.

Pests & Diseases:

• Bluebonnets are at their most vulnerable as seeds and tiny seedlings.
• Birds can be an issue with seeds that have been broadcast without sufficient soil to hide them.
• Pillbugs (also known as roly-polys or sow bugs) are the main insect predator for Bluebonnet seeds and seedlings.
• Too much water can result in damping-off disease which will kill the seedling.

Note: Bluebonnets are not edible, and can be toxic depending on season and species. Most toxicity is present in seeds, and if planting with children, care must be taken to ensure little hands do not put them in their mouths.

Fertilizing: No extra fertilizer is necessary, but Bluebonnet will not be harmed if you apply a balanced organic fertilizer in early spring, which may result in bigger plants.

Mulching: In nature, soil erosion and foliage that dies back is all the mulch Bluebonnets need to germinate. In fact, Bluebonnets are a legume, and as such are a good nitrogen fixer for poor soils. We do not recommend mulching, as it will conserve too much moisture and limit light for germinating seeds.

• In humid climates or those with higher rainfall, moisture may cause seedlings to dampen off with fungal disease.
• You may also be dealing with soil that is too heavy and needs amending before planting to improve drainage.
• If you're planting in spring, remember to scarify the seeds adequately.
• Excessively hot springs can mean a short bloom season for this lupine, for whom hot weather is a signal to set seed and finish its lifecycle as compost for those seeds.
• You may also be sowing your seeds too late in the season for them to put down strong roots for winter. Try sowing a little earlier in fall than you did the previous season.
• If you’re having difficulty with getting your seeds started because of the ravages of birds and/or pill bugs (two of the worst pests for bluebonnet), consider starting them in trays outdoors and transplanting when the plants are larger.