[Objectives] The research aimed to study the effect of sludge extract on the growth of Zinnia elegans, and evaluate its possibility of application. [Methods] Z. elegans was taken as research object, and the effect of sludge extract on the growth indexes of Z. elegans was studied. [Results] The sludge extract can obviously promote the growth of Z. elegans, and the growth indexes were significantly improved when compared with the control group. The application effect was close to that of foliar fertilizer purchased in the market. In each treatment group, the low concentration of sludge extract did not significantly promote the growth of Z. elegans, while too high concentration could inhibit its growth, and the optimal dilution ratio was 600 times. [Conclusions] Further preparation of amino acid foliar fertilizer from sludge extract and its application in planting garden plants can realize the resource utilization of sludge and has a good development and application prospect
