Bluebonnets require full sun and well-drained ordinary soil of moderate alkalinity. They will not tolerate heavy clay soils, so if you have dense clay soil, grow them in raised beds amended with compost and sand to give them the good drainage they need. Bluebonnets are drought-adapted; do not overwater them during active growing periods.
HOW BLUEBONNETS GROW AND WHAT THEY NEED
Bluebonnet’s large, hard-coated seeds respond best to late summer/fall planting as exposure to winter soil abrasion. Precipitation and weather changes break down the naturally tough outer coat of the seeds to produce germination in fall or early spring. As spring breaks, plants respond to sun and warmth, and then bloom gloriously, attracting happy bees and butterflies. The beautiful flower spikes are deep blue with white tips. After flowering, seedpods form, dry and drop seed to rebloom the next season.
SOWING AND GROWING BLUEBONNETS
Plant seeds in late summer or early fall to overwinter and bloom the next spring (in hard winter areas, sow in very early spring). Plant in ordinary garden soil, preparing the soil by removing weeds, grass and stones. Evenly loosen the top 4 inches of soil with a shovel or digging fork and break up soil clumps, then rake smooth.
Broadcast the seed over the seed bed, aiming for 6 inch spacing. Cover lightly with soil, tamping it down to make sure the seeds get good soil contact. Water in well at planting time, then keep moist but on the dry side until seasonal rains take over. Seeds may take 3 to 4 weeks to slowly and unevenly germinate. Foliage rosettes of 5-7 leaves will develop close to the ground and overwinter that way. (If cold weather comes on, seeds may delay germination until the next spring.) After germination, seedlings develop long tap roots and usually don’t require additional irrigation.
In mild early spring weather, bluebonnets will actively begin growing again. Plants rapidly develop multiple 8-12 inch flowering stalks that bloom in a gorgeous blue color with white tips. After the colorful flowers fade, green seedpods form. When they are dried up and dark brown, pods pop open and drop seed to self-sow for next spring’s flowers.