Flowering phase regulation and control method of bougainvillea speetabilis for bridge body greening

The invention provides a flowering phase regulation and control method of bougainvillea speetabilis for bridge body greening. According to the flowering phase regulation and control method of the bougainvillea speetabilis for bridge body greening, branches of the bougainvillea speetabilis are shaped and trimmed 60-70 days before a flowering phase, so that the plant nutrition loss and consumption are avoided; soil loosening and root breaking are achieved, so that the root activity is improved, and preparation is made for sufficient absorption of fertilizer; decomposed organic fertilizer is applied to provide plant compound nutrition; exogenous hormones are added after first water control operation is carried out on the bougainvillea speetabilis, so that flower bud differentiation of the bougainvillea speetabilis is guided, plant differentiation is promoted, and the flower quantity is increased; and secondary water control operation is carried out on the bougainvillea speetabilis to strengthen drought stress of