Texas Bluebonnet, Lupinus texensis: State Flower of Texas
Description: Texas Bluebonnet, Lupinus texensis, is a low-growing
Texas icon. It is one of five Bluebonnets recognized as the Texas
State Flower; the other four are L. subcarnosus, L. havardii, L.
concinnus and L. plattensis. The five lupine species grow in different
areas of Texas, with L. texensis predominating in Central and North
Texas. In spring, blooming L. texensis is a common sight along
roadsides and fields and is increasingly cultivated in sunny front
yards. It is the easiest of the species to cultivate, usually growing up
to 18 inches tall and equally wide, with flowers held higher. It has
oblong palmate light-green compound leaves, usually with five
leaflets. Healthy plants have a tap root and as legumes, Bluebonnets
are capable of forming symbiotic nitrogen fixing root nodules with
soil bacteria called rhizobia, allowing them to enrich the soil with
nitrogen.
Flowers and Seeds: Bluebonnets usually bloom from early March to
mid-April or later depending on spring temperatures. The flowers are
held on a 7-12 inch stalk, with deep bright blue flowers at the bottom
to white on the top. All-white, pink and maroon cultivars are
available. After the flowers fade, seeds form. Because it is an annual,
the flat 1/8 inch seeds must fully mature in the pod and fall to the
ground to assure a display next year without re-planting.
Planting sites: Texas Bluebonnets should be planted in full sun, at least 8-10 hours a day. They prefer
well-drained soils and are drought tolerant.
Watering Instructions: Texas Bluebonnet seed may be watered after planting. The plant is drought
tolerant and will survive during long dry spells. It will rot if well-watered.
Comments: In Texas, flowering Bluebonnets let us know spring has arrived. Texas Bluebonnet is a
winter-hardy annual and may be transplanted into a sunny location, ideally in fall. To establish
Bluebonnets from seed, start in summer or early fall. Scarify the seed by rubbing with sandpaper, then
rake or press the seeds into the soil, barely cover them with soil and water once. If available, rhizobial
inoculant should be applied to establish the nitrogen fixing root nodules that help Bluebonnets grow.
Frequently, rhizobia are already in the soil. Bluebonnets are beautiful in large drifts or grown in welldrained containers. They are frequently inter-planted with summer- or fall-flowering plants that emerge
as the Bluebonnets are setting seed and senescing. These include Zexmenia (Wedelia texana), Mealy
Blue Sage (Salvia farinacea), and Lantana (Lantana urticoides). Bluebonnets provide nectar for bees
and are the larval host for the Hairstreak and Elfin butterflies. Use caution because Bluebonnets,
especially the seed, can be toxic if ingested.
Look for the NICE! Plant of the Season signs and information sheets on your next visit to a participating
North Texas nursery. Thank you for using native plants in your landscapes.
Written by Dr. Becca Dickstein
