Professional Tree Care

Greater Harmony Between Agriculture and the Environment
Research Year: 

Arizona's population remains concentrated in or around the metropolitan areas of Phoenix and Tucson. These two areas account for 80 percent of the state's population and they are growing. There are other concentrations of growing populations in a number of smaller communities. With this growth comes new residents to Arizona and more homes to accommodate these newcomers.

This influx equates to a tremendous number of trees being planted by people with limited knowledge of tree growth and care requirements. A large number of landscape installation and maintenance companies appear to be vying for business in a very competitive market. This leads to quick and dirty installation and maintenance contracts based primarily on the ‘‘bottom line.''

Certified arborists, who are trained in tree care and pruning, have been few in Arizona. The number of certified arborists in 1996 was 17 statewide. These professionals were primarily employed by utility companies, cities and three national tree care companies contracted to the same utility companies and cities.

This situation offered the opportunity for the University of Arizona Cooperative Extension and industry to collaborate in developing programs to train more tree care professionals. As a statewide team, with support the Arizona Community Tree Council, plans were made to offer educational programs for people who could eventually apply to the International Society of Arboriculture (ISA) for testing to become certified arborists.

Description of Action: 

Since 1996 the University of Arizona Cooperative Extension (primarily in Maricopa County) has joined with certified arborists to conduct the intense 48 hours of training required. Six trainings have occurred in Phoenix, attended by participants from across the state. Three training courses have been offered in Yuma, drawing people from California as well as Arizona.

Trainings began in Tucson and Show Low in 2001. Instruction runs 8 hours per day and covers tree biology; soil and fertilizer; cabling and bracing; plant identification; insect pests; diseases; plant problems and identification; construction; installation; pruning; electrical hazards; and climbing. An optional 6-8 hours was offered as a pre-test session for those planning to take the certification exam. The goal to train motivated professionals who then decide to become certified arborists is the essence of extension education. Due to potential conflict of interest inherent in certification the instructors from extension are not certified but are the primary resource for the initial training and the required continuing education.


Since this concentrated educational program began, the number of certified arborists in Arizona has increased dramatically. By October 2001 there were 261 certified arborists, a nearly sixteen-fold increase over the 17 working in the state in 1996. These university-trained professionals offer their services to a wide range of customers. Their work is licensed, bonded, and insured, and regulated by the ISA to maintain high standards of work.

Funding Agencies: 

Arizona Community Tree Council; Participant fees

Conact Name: 
Terry Mikel
Contact E-mail: 
Contact Address: 

Cooperative Extension

The University of Arizona

4341 E. Broadway Road

Phoenix, AZ 85040-8807

Tel: (602) 470-8086, ext. 310, FAX: (602) 470-8092