I potted mint with flowers. Why are the leaves so small?

Hello. It may be the problem of insufficient nutrients, or it may be that the pot is too small, the plants are too big, and the roots are too full in the pot, resulting in insufficient nutrients and trace elements. It may also be that the soil is not good. Mint should never be like mud on the roadside. In this case, you can try to change the soil and buy some professional sterile soil in the local flower and bird market. Clean and fat. Hope to adopt, thank you.