Light: Bluebonnet needs a sunny position to do well. 8-10 hours of full sun is recommended.
Soil: Texas bluebonnet is a survivor; however, it needs well-drained soil – preferably on the sandier side – to thrive. Seeds can germinate in a heavy clay soil, but will eventually peter out due to an excess of moisture. If planting in containers, an average potting soil can be used, but good drainage is essential.
Spacing: If broadcasting seeds, rake and roughen area well and plant at a rate of approx. 2 oz per 100 square feet (1 pound per 700 square feet). 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: Bluebonnet is an annual plant which germinates, grows, flowers and sets seed over the course of one year. If conditions are favorable in your garden for the plant to set seed and re-seed itself, you can be assured of a carpet of bloom for years to come.
Planting Times: This is a fall-planted seed for spring flowering. Transplants should also be planted in the late fall.
How to Grow Texas Bluebonnet Throughout the Season
Growth Habit: Texas bluebonnet germinates in late fall and creates a low growing rosette of foliage (whorled leaves) 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 and die back to the ground.
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.
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.
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.
Mulching: In nature, soil erosion and end-of-season detritus (the dieback and fall-off of the plant’s foliage) is all the mulch self-seeded bluebonnet needs to germinate. Heavier mulches will conserve moisture and limit light to germinating seeds and is not a good idea.