Why may bougainvillea fail to flower?
Bougainvillea includes woody climbers and shrubs derived from Bougainvillea spectabilis and other species or hybrids. The large colorful structures are mainly bracts around much smaller true flowers. Cold tolerance varies among species and cultivars.
Light, feeding, and growth balance
Strong light supports colorful bracts. Deep shade or excessive nitrogen can favor leafy growth. Roots need drainage rather than continuous saturation. Deliberately inducing dangerous drought is not an appropriate flowering strategy. Assess container volume and root health instead of treating severe root restriction as a universal cure.
Support, pruning, and winter
Train shoots onto strong supports and prevent prickly branches obstructing walkways. Prune in relation to flowering habit and climate. Cold regions may require protected container culture. Handle sap and sharp structures carefully. A plant sold in full color is not guaranteed to bloom continuously throughout the year under ordinary indoor light.