765 ILCS 130/3
When 2 or more persons have lands adjoining, each of them shall make and maintain a just proportion of the division fence between them, and if such fence shall be a hedge fence, then the owner or owners of such hedge fence shall, during the year after such hedge has attained the age of 7 years, cut back or trim such hedge fence to a height not to exceed 4 feet, and shall at least once in every 2 years thereafter, cut back or trim such hedge fence to the height of 5 feet. The provisions of this section shall not apply to any hedge fence protecting either an orchard, buildings or wind break, nor shall the provisions of this Section apply to any such fence for the preservation of wildlife and protection against soil erosion. Such hedge fences protecting wildlife, or orchards, or buildings or windbreaks, and such fences protecting against soil erosion shall not exceed 60 rods in length. If the owner or owners of such hedge fence shall fail or refuse to comply with the provisions of this act, on or before the 15th day of June in the year that such hedge should be cut or trimmed, any one of the owners of such division fence having complied with the provisions of this act may give the owner or owners, or their agents, of any such uncut or untrimmed hedge, 10 days notice, in writing to cut or trim such hedge. And should the owner or owners, or their agents so notified fail or refuse to comply with such notice it shall be lawful for the person giving the notice to cut or trim or cause to be cut or trimmed, in accordance with law, and the cost and damage of cutting or trimming such hedge may be recovered off of the owner or owners of such hedge before any court of competent jurisdiction.
765 ILCS 130/3