Gaura coccinea, scarlet gaura or scarlet beeblossom, is a low, wiry perennial native to the Great Plains and intermountain West, from Montana and the Dakotas south through Texas and west to Arizona and Idaho — a much broader, colder-hardy range than its Texas-and-Louisiana relative Gaura lindheimeri, and a genuinely tougher plains prairie plant. Its small flowers open white to pale pink in the evening and fade to deepening pink and scarlet red as they age, so a single flowering stem shows several colors at once — pale newly opened blooms above, darker aged ones below.
Like the rest of the genus it runs on a deep taproot that makes it exceptionally drought tolerant once established but intolerant of transplanting or heavy, wet clay — site it once, in lean, sharply drained soil, and leave it alone. It stays lower and more compact than Gaura lindheimeri, reading as a true short-grass prairie wildflower rather than a border perennial, and blooms nearly continuously from late spring to frost with minimal deadheading.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.
Crown Rot
Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.
Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.