Sims Tree Health Specialists Inc

Sims Tree Health Specialists, Inc. was founded in 1972.

We are professional arborists providing preservation plans, consulting, diagnosing and treatment of stressed, sick trees and/or trees impacted by construction.


If you need help with your tree, and live in Southern California, call Sims at (951) 685-6662. If you are out of our service area, visit for an arborist local to you.

Treatments vary from efforts to save heavily damaged or sick trees to annual maintenance of trees. Treatment options include monitoring programs, traditional pesticides, organic pesticides and beneficial fungi, bacteria and stimulants.

Sims has (9) International Society of Arboriculture (ISA) certified arborists.

Gary Sims – ISA certified Arborist #WC-1211, CA agricultural Advisor #6491, CA Agricultural Applicator #QAL31895.

Susan Sims – Biologist, ISA Board Certified Master Arborist #WE-0286B, CA Certified Urban Forester #122, CA Agricultural Advisor #1096, CA Agricultural Applicator #QAL-31179.

Kevin Sims – ISA Certified Arborist #WE-8449A, Research projects.

Keith – ISA Certified Arborist #WC-6668, CA Agricultural Applicator #QAL39022, Citris and avacado health care specialist.

Dale – ISA Certified Arborist #WC-4234A, CA Agricultural Applicator #QAL37914, Tree health care specialist.

Dale – ISA Certified Arborist #WC-6019, CA Agricultural Applicator #QAL39061, Tree health care specialist.

Robert "Monty" – ISA Certified Arborist #WC-0730, CA Agricultural Applicator #QAL39092, Tree health care specialist.

Bob – ISA Certified Arborist #WC-1907, CA Agricultural Applicator #QAL37120, Tree health care specialist.

All of our technical staff attend classes and seminars throughout each year to stay at the top of their field.

Tree care seasons to remember (besides other tree care needs):

Fall – Most important citrus spray during the year. Organic or traditional sprays for annual cleanup of scale insects, mites, etc.

Winter – Dormant sprays both organic or traditional for the annual cleanup of overwintering insects, mites, some disease organisms. Good for sycamores deciduous fruit trees, etc.

Spring – Protect stressed pines from borers with topical or systemic borer protectants. Avoid pruning pines during any but the coldest weather.

Late Winter or Spring – Eucalyptus soil drench for control of lerp psyllids and borer protection.