Query regarding Lawn Culture that I performed.

MY question is regarding the lawn culture results. During my last lab class, I performed the Kirby-Bauer Disk Diffusion Susceptibility Test. To attain results in this experiment I needed to perform Lawn culture. However, after I performed the lawn culture and placed the antibiotic disks, after incubation no growth was observed.

I would like to know, why no growth was observed?

Thank you.