IPMC 2021 Section 302.4 Weeds.
Premises and exterior property shall be maintained free from weeds or plant growth in excess of 12 inches. Noxious weeds shall be prohibited. Weeds defined as grasses, annual plants and vegetation; this term shall not include cultivated flower gardens.
IPMC 2021 302.4.1 Responsibility.
The property owner is responsible for cutting grass and weeds between his property lines and the back of the curb or the edge of pavement. In addition, property owners abutting alleys (and ROWs) shall be responsible for mowing and cleaning the alley to the midpoint of the alley or ROW.
Ordinance Part II, Chapter 5, Article I, Section 5-12, IPMC Section 302, #1588-06-2022
IMPORTANT TO NOTE:
Regardless that you have a fence around your backyard, you are still responsible for the grass and weeds outside of the fence to the midpoint of the alley behind your property. If you have no alley, you are responsible to the back of the curb or the edge of the street—whichever applies.
*Grass cuttings and leaves shall not be blown into the street. They should be swept or blown back into the yard.
This IS an example of a high grass violation.

This IS NOT a high grass violation.

Failure to abate a violation may cause a citation to be issued. Penalties up to $2000 per day may be imposed.