The clusters of vivid blue, pea-like flowers with a cap of white blooms on top are what make Texas bluebonnets so attractive. In full-sun garden plantings, along roadsides, and in sunny fields, these pretty pollinator plants blossom in the spring. You can start the plants by spreading seeds in the fall, or they can be let to self-seed.
The Texas Bluebonnet, or Lupinus texensis, is the state flower and a well-liked wildflower that may thrive in many of your gardens even outside of Texas. This annual plant, related to lupines, is hardy in USDA zones 4–8, and it is easily grown from seed.
When handled, the seeds can result in contact dermatitis, and all plant components are poisonous to humans, dogs, cats, horses, and grazing animals.
Table of Contents
ToggleTexas Bluebonnet Overview
Common Name | Â Texas Bluebonnet, Texas Lupine, Buffalo Clover, Wolf Flower |
 Botanical Name |  Lupinus texensis |
 Family |  Lupinus |
 Plant Type |  Annual |
 Mature Size |  1 – 2 feet tall, 1-2 feet spread |
 Sun Exposure | Full sun |
 Soil Type |  Chalk, clay, sand, loam, well-drained |
 Soil pH |  Neutral, Acidic, Alkaline |
 Bloom Time |  Spring |
 Flower Color |  Blue |
 Hardiness Zones |  4-8 USDA |
 Native Area |  Texas and the American Deep South |
 Toxicity |  Plant parts are toxic if ingested |
When to Sow Bluebonnet Seeds?
The seeds for Texas bluebonnets should be sown in October through November because they are cold-hardy annuals that bloom in the spring. The cooler weather is necessary to assist the bluebonnets’ root structure development so that blooming happens the following spring. The temperatures in the hardiness zones of early autumn will aid in the germination of the seeds.
The flat, tiny seeds have multiple colors. Commercially sold seeds germinate quickly, however, seeds that are harvested take longer to germinate. While some seeds may not sprout upon planting, others may thrive within a few months. When growing conditions are unfavorable, such as a protracted drought, the delayed germination helps secure the survival of the species. Commercially available seeds are either sacrificed or treated to weaken the seed coating, allowing the seeds to sprout in 10 days.
Texas Bluebonnet Care
The Texas bluebonnet is a hardy wildflower that doesn’t require much care. It has adapted to withstand extreme circumstances like drought and undernourished soil. Planting seeds or seedlings in full sun, with well-draining soil, minimal watering, and minimal fertilization are the keys to success in home gardens. Put another way, don’t bother the plants! Texas’s severe climate is nothing new to bluebonnets.
Usually, the bluebonnets bloom for almost a month, starting at the end of March. A green seedpod forms about mid-May, The seedpod will first turn brown, then yellow. The pod will split open to release the tiny, hard seeds that will develop next when the seeds are ready.
Light Requirements
Texas bluebonnets require eight to ten hours of sunlight per day to flourish. They can withstand some shade, but the number of flowers may decrease.
Soil and Potting
As long as the space drains properly, the plants will grow in any kind of soil—sandy, loam, clay, or chalk. Although the pH of the soil is crucial, they will thrive in a slightly alkaline growing medium.
Watering
Watering Texas bluebonnets is especially crucial just after the seed is sown. It is important to keep the soil damp but not wet until the seed starts to sprout. After that, water established plants sparingly until the top inch of soil dries. Don’t let the ground stay damp.
Temperature and Environment
Texas bluebonnets require mild autumnal conditions to promote seed germination and colder wintertime temperatures to aid in the development of the root system necessary for early spring blooming. The visible sections of the plants have died back and are unaffected by the high humidity of summer. USDA hardiness zones 4 through 8 are ideal for Texas bluebonnet growth.
Fertilization
Texas bluebonnets are a wildflowers and don’t need extra fertilizer. By forcing the leaves to absorb the majority of the nutrients, applying a commercial fertilizer high in nitrogen will frequently lower the amount of blooms produced.
The soil contains a bacterium called Rhizobium, which bluebonnet roots use to enhance plant growth and flowering. Nitrogen fixation, or converting atmospheric nitrogen into a form that plants can use, is improved by rhizobium. Nodules—small, spherical lumps on the roots of bluebonnet plants that contain bacteria that fix nitrogen—appear once the plants have taken root.
Types of Bluebonnets
Although Lupinus texensis is probably the most well-known, readily available, and simple to grow bluebonnet.
Lupinus subcarnosus:Â Often referred to as the sandy land bluebonnet, it grows in deep sandy loams that stretch from Leon County in the southwest to LaSalle County and down to the northern portion of Hidalgo County. The plant’s leaves have silky undersides and are blunt, occasionally notched. Maintaining this species on clay soils is difficult, as it achieves its peak bloom in late March.
Lupinus Havardii:Â Known as the Big Bend or Chisos Bluebonnet, it is a bigger variety with flowering spikes that can reach a height of three feet. It is hard to grow outside of its native habitat and is found in early spring in the flats of the Big Bend region.
Lupinus concinnus:Â The flowers of this little bluebonnet, which range in height from two to seven inches, are a mix of white, pink purple, and lavender. It is rare in the Trans-Pecos region and blooms in the early spring.
Lupinus plattensis:Â It is the only perennial species in the state and can be found in the sandy dunes of the Texas Panhandle. Known by several names, including the Nebraska Lupine, Plains Bluebonnet, and Dune Bluebonnet, it reaches a height of approximately two feet and blossoms in the middle to late spring.
Pruning
Pruning the Texas bluebonnet is not necessary, but it may stimulate the growth of new side shoots and flowers if spent early blooms are removed. The plant can be chopped to the ground or, if it was planted in a field, mowed to the ground when the blooming season is over and it has died down. Removing the plants should ideally wait until the seed pods have matured and dried.
How to Grow Texas Bluebonnets From Seed?
Although some specialty wildflower nurseries may sell seedlings, most gardeners start their Texas Bluebonnets from seed. You have two options for sowing the seed: straight into the ground or in a covered seed starter.
So that the plants have time to establish root systems during the colder winter months, seeds should be sown in October or November. The bluebonnets take about a year to go from seed to plant to flower to seed again. It can take a few years for mature plants to emerge from collected seeds or seeds that are planted organically after the seedpod pops. Select commercially available seeds or scarify gathered seeds for more consistent yields.
- Scarify the seeds by physically nicking them with a knife (for small quantities), rubbing them with sandpaper, or freezing them overnight. Then, immediately cover the seeds with boiling water and let them soak at room temperature for a few hours.
- After the seeds are scarified, sow them in a moist seed-starting mixture so they will sprout rapidly. For a few weeks, make sure to water, particularly in arid conditions.
- Since the plants can withstand drought, once the seedlings have several leaves, move them into the garden and water them less frequently.
Take caution not to bury a transplanted bluebonnet too deeply. You’ll see that a core structure like a crown is where all of the leaves originate. If this crown is buried, the plant will wither away. Plant eight to ten seeds per square foot if you are directly putting seeds into the garden. Not all seeds will sprout. Firmly press the seeds into the loose, tilled soil with your hands.
Slopes facing south and west will promote earlier spring growth and blossoming; pick a sunny, well-drained spot with slightly alkaline soil.
Bluebonnet seeds dislike soggy soil, even though they need some moisture to develop and flourish. Occasional watering will assist ensure success if there is little rainfall in the fall or winter.
Overwintering
Overwintering seeds or seedlings is as easy as leaving them alone once they are planted in the fall. Bluebonnets grow into ground-hugging rosettes that can reach up to 12 inches in spread but are just a few inches tall. This is the plant’s natural tendency, and it won’t grow quickly until the springtime warmth triggers the initiation of flower stalks. After the first freeze, the lowest leaves may turn red. Growing beneath the leaf rosette is a substantial mass of roots.
Common Pests and Plant Diseases
Plowbugs and sowbugs are the most prevalent insect pests that can kill seedlings and transplants. These insects typically prey on plants at night and launch attacks. In the first month following planting, minimize moisture, remove extra mulch, and, if necessary, distribute pillbug bait around newly established or emerging plants to ensure seedling and transplant survival.
With seedlings, damping off, a fungal disease that results in stem rotting, can happen. Avoid planting in beds where damping-off issues have already occurred, use transplants rather than direct seeding into the bed, and don’t overwater to reduce damping-off issues.
How to Get Texas Bluebonnets to Bloom?
If the bluebonnets are planted in full sun, they will bloom the most profusely. Steer clear of overfertilization and overwatering. Plants that are seeded or planted in the spring rather than the preceding fall will either not bloom at all or will blossom sparsely. Everything depends on timing.
Common Problems With Texas Bluebonnets
- Overwatering
- Over-fertilization
- Too much shade
- Pillbugs and sowbugs eating young plants
- Planting seeds or seedlings in the spring
Also Read: Top 15 Best Green Flowers For Your Garden