Arboriculture 101

MU Landscape Services/Mizzou Botanic Garden (MUBG) Managers, Jenna Rozum, horticulture manager, and Blair Crosby, operations manager, are certified arborists, but, as Rozum pointed out, “There’s more that I don’t know about trees than I do.”


Our certifications better prepare us to know what to look for when engaging a professional arborist; what questions to ask of professionals who have dedicated their lives to this work,” Rozum added.


Both agree that their training allows them to assess storm damage and structural risk in regard to trees growing on campus. As far as diagnosing the wide range of potential problems trees might encounter and myriad symptoms they might exhibit, a professional assessment by an arborist is recommended.


“When trying to diagnose a problem with a tree, MU Extension is a good place to start,” said Crosby. The Missouri Department of Conservation (MDC) also offers diagnostics.

Landscape Services removes tree near Jesse Hall


What is arboriculture?

Humans have practiced arboriculture — defined as the cultivation and care of trees, shrubs and woody plants for shade and landscaping — for hundreds of years. One of Aristotle’s pupils, Theophrastus, wrote about transplanting trees and treating tree wounds in 300 BCE.


Most all of us with a home landscape are practicing arboriculture at a basic level, planting trees and caring for their basic needs by watering and mulching them. But that does not make us arborists.


Arborists are career professionals dedicated to sustaining the life and long-term benefits of trees. They are uniquely qualified to advise and help with solutions for tree injury including skilled removal in extreme cases. Arborists aid in the diagnosis and treatment of insect and disease damage. Their skillsets equip them to correctly prune trees for health, appearance and safety. They also can advise on planting and caring for new trees. A qualified arborist will never suggest topping a tree and will never wear spurs to climb a tree. When hiring an arborist, it is important that he or she is certified.


The International Society of Arboriculture (ISA) maintains a website,, that “provides the public with educational information about the benefits of trees and how to properly care for trees in the home environment.”


In addition to several downloadable tree care and educational activity publications, ISA provides a link to the National Tree Benefit Calculator on the website. Enter a zip code, a tree species, the diameter of a tree’s trunk, and select its land-use and the calculator will make a simple estimation of the tree’s overall benefit: stormwater interception, its contribution to your home’s value, and its impact on energy conservation, air quality, and reduction of atmospheric carbon (CO2). Enlightening and fun!

MU Extension Plant Diagnostics

MU Extension’s Plant Diagnostic Clinic (PDC) assists county extension specialists, commercial businesses and private citizens with plant diagnostics: maladies, diseases and unknown plant and insect identification. Missourians may take advantage of the service by sending a quality plant material sample/insect specimen to the clinic. Detailed submission guidelines are available on the extension website. PDC also offers the opportunity to submit photos of problems by email to A small fee is charged for diagnostic services.

MDC Tree Diagnostics

Robbie Doerhoff, a forest entomologist with MDC, said she handles about 300 inquires a year from the public regarding tree and forest health. She said Missourian’s may contact her directly at or can submit tree-health related questions through a form on MDC’s website: Contact Us | Missouri Department of Conservation (


“Once people are in contact with me, they can email photos of their issue,” Doerhoff said. “Usually, I can diagnose the problem from pictures and offer the appropriate next steps, which may include contacting a certified arborist or a consulting forester. This information is free of charge.


“Unfortunately, we don’t have the staff or lab capacity at MDC to handle many physical samples from the public. Instead, we largely process samples that are collected by MDC foresters, mostly from public lands. Homeowners with landscape tree issues are encouraged to use the affordable services provided by the University of Missouri’s Plant Diagnostic Clinic. Landowners with forest health issues are encouraged to work with the local MDC forester or private land conservationist in their county; contact information for those staff can be found here: Local MDC Contacts | Missouri Department of Conservation (


MDC also offers online advice on how to hire an arborist.