Abstract: In order to improve the rooting rate of crape myrtle（Lagerstroemia indica L.） cuttings, and regulate the flowering time of cuttage seedlings in the same year, L₈（4×2⁴） was designed by four-factor mixed orthogonal experiment to study the effects of cutting matrix, spike length and leaf retention methods on cuttings rooting of two kinds crape myrtle of Red Wei and Er Hong. And fertilization was controlled to make cuttage seedlings bloom in that year. The results showed that planting species and substrate ratio were the most important factor affecting cutting rooting, followed by the length of spike and leaf retention methods, and application of high P and K fertilizer after transplanting helped crape myrtle blossom in the same year. Integration of flower formation technology for cutting 1 time of Red WeiThe rooting rate of the combination of 13~15 cm cutting length of Red Wei + retaining 2 leaves + peat soil∶vermiculite=1∶1 reached 100%. The cuttings were transplanted together with the non-woven bag 17 d after being cut, and 0.1% concentration of Huaduoduo No. 2 fertilizer was applied once every 7 d 10 days after being transplanted. After being transplanted for 22 days, the cuttings began to flower, and the full flowering period lasted from September 25th to October 17th, with a flowering rate of 72.5%. The rooting rate of the combination of 13~15 cm cutting length of Er Hong + leaf shearing 1/2 + peat soil∶vermiculite=1∶1 was 52.4%, the average number of roots was 4.5, and the plant did not flower that year after being transplanted.

Key words: crape myrtle（Lagerstroemia indica L.）, softwood cuttage, cutting matrix, take root, one-time flower formation