Tex. Transp. Code § 392.003

The commission by rule shall establish a program under which the department may accept from any source, including an individual or a private business or organization, donations of landscape materials for state highways, as authorized by Section 201.206. The program may provide for the department to enter into an agreement with an individual or private business or organization for the individual or entity to provide, at no cost to the department, services for the installation or maintenance of landscaping on state highways.