In counties of less than 3,000,000 inhabitants, a county board may provide for the cutting of weeds on lots in subdivisions in residential areas in the unincorporated area of the county or any part thereof, when the owners of the subdivision lot refuse or neglect to cut them, and may collect from the owners the reasonable cost thereof. Notice of intention to cut weeds shall be given to the owners of subdivision lot involved at least 15 days before such action is intended to be taken, by mailing a written copy of such notice to the last known address of each such owner or owners. This cost is a lien upon the subdivision lot affected, superior to all other liens and encumbrances, except tax liens; provided that within 60 days after such cost and expense is incurred the county, or person performing the service by authority of the county in his or its own name, files notice of lien in the office of the recorder in the county in which such subdivision lot is located or in the office of the Registrar of Titles of the county if the subdivision lot affected is registered under the Torrens system. The notice shall consist of a sworn statement setting out (1) a description of the subdivision lot sufficient for identification thereof, (2) the amount of money representing the cost and expense incurred or payable for the service, and (3) the date or dates when such cost and expense was incurred by the county. However, the lien of such county shall not be valid as to any purchaser whose rights in and to such subdivision lot have arisen subsequent to the weed-cutting and prior to the filing of such notice, and the lien of the county shall not be valid as to any mortgagee, judgment creditor or other lienor whose rights in and to such subdivision lot arise prior to the filing of such notice. Upon payment of the cost and expense by the owner of or persons interested in such property after notice of lien has been filed, the lien shall be released by the county or person in whose name this lien has been filed and the release may be filed of record as in the case of filing notice of lien.