Abstract: In order to develop the proprietary fertilization mode of polychromatic crape myrtle,this paper studied the differences in growth and flowering index of polychromatic crape myrtle's traits under the influence of seven factors through orthogonal testing by using three varieties as the research objects.The results showed that the fertilization method and the fertilizer ratio at flowering time were the two most important factors affecting the traits of polychromatic crape myrtle.The two factors of fertilization time had little effect on either growth traits or flowering traits.The topdressing method with two foliar applications should be adopted.The base fertilizer should mix soil with balanced fertilizer.The high-potassium fertilizer should be used for topdressing at the leaf-developing period,and the high-phosphorus or balanced fertilizer should be used for topdressing at the flowering period.Bringing forward the topdressing time to the flowering period may result in good effects.

Key words: Polychromatic crape myrtle;NPK;Growth trait;Flowering trait;Fertilization mode