Reference
Tree Care Glossary
Plain-language definitions of the terms our ISA Certified Arborists use on Southern Wisconsin estimates: tree diseases, pruning standards, professional credentials, treatments, equipment, and tree anatomy. Bookmark this page — every term has a direct link.
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Diseases & Pests
8 terms
Oak Wilt(Ceratocystis fagacearum)
#oak-wilt- A fatal fungal disease caused by Bretziella fagacearum that kills red oaks within weeks of infection and slowly degrades white oaks over years. The fungus blocks water-conducting vessels in the xylem. In Wisconsin, it spreads above-ground via sap beetles attracted to fresh pruning wounds (April–October) and below-ground through root grafts between neighboring oaks. Oak wilt diagnosis & treatment in Janesville
Emerald Ash Borer(EAB, Agrilus planipennis)
#emerald-ash-borer- An invasive jewel beetle whose larvae feed on the cambium of ash trees, girdling them within 3–5 years of infestation. Confirmed throughout Dane and Rock counties since the early 2010s. Untreated ash trees die. Healthy ash with less than 30% canopy decline can be saved with emamectin benzoate trunk injection on a 2–3 year cycle. EAB treatment in Dane County
Dutch Elm Disease(DED, Ophiostoma novo-ulmi)
#dutch-elm-disease- A fungal vascular disease that wiped out most American elms in Wisconsin in the mid-20th century. Spread by elm bark beetles and root grafts. Surviving elms in older Wisconsin neighborhoods still face DED pressure; protective propiconazole injection on a 2–3 year cycle keeps high-value specimens alive.
Anthracnose
#anthracnose- A group of fungal leaf and shoot diseases affecting maples, sycamores, oaks, and ash. Symptoms include irregular brown leaf blotches and early leaf drop in cool, wet springs. Rarely lethal but cosmetically destructive. Best managed with sanitation (removing fallen leaves) and improved air circulation through structural pruning.
Apple Scab(Venturia inaequalis)
#apple-scab- A fungal disease of apple, crabapple, and pear trees. Symptoms: olive-brown spots on leaves and fruit, premature defoliation by mid-summer in heavy years. Common throughout Southern Wisconsin. Managed with resistant cultivars, sanitation, and protective fungicide sprays during early-spring leaf-out.
Bur Oak Blight(BOB, Tubakia iowensis)
#bur-oak-blight- A late-season fungal leaf disease specific to bur oaks, increasingly common in the upper Midwest. Symptoms appear July–August: wedge-shaped brown leaf areas and dropped leaves with persistent dead petioles. Severe in successive wet springs. Trees with chronic infection benefit from propiconazole injection.
Pine Wilt(pine wood nematode)
#pine-wilt- A fatal nematode disease of Scotch and Austrian pines, spread by sawyer beetles. Trees turn rapidly brown and die within a single growing season. White and red pines have moderate resistance. No treatment exists for infected trees; removal and proper wood disposal (not stored as firewood) is required.
Two-Lined Chestnut Borer(Agrilus bilineatus, TLCB)
#two-lined-chestnut-borer- A native borer beetle that attacks oaks already weakened by drought, construction damage, or root disturbance. Larvae girdle the cambium, killing branches from the top down. Often the final blow on stressed oaks. Prevention focuses on keeping oaks vigorous; treatment for active infestation is rarely successful.
Pruning & Techniques
7 terms
ANSI A300
#ansi-a300- The American National Standards Institute's standard for tree care operations — the accepted industry standard for pruning, fertilization, cabling and bracing, and other tree-care work in the United States. ANSI A300 defines proper cuts (at the branch collar, no flush cuts, no stubs), maximum canopy removal (≤25% in a single growing season), and the objectives for each pruning type. Tree Wise Men follows ANSI A300 on every job. ANSI A300 tree trimming service
Crown Cleaning
#crown-cleaning- The selective removal of dead, dying, diseased, weakly attached, or low-vigor branches from the canopy. The most common type of pruning, and the foundation of mature-tree health management. Crown cleaning is essential for storm-damage prevention and is recommended every 3–5 years for mature shade trees in Wisconsin.
Crown Reduction
#crown-reduction- Reducing the height or spread of a tree by pruning leaders and branches back to lateral branches at least one-third the diameter of the cut stem. The proper alternative to topping — preserves the tree's natural form and structural integrity. Used when trees have outgrown their space or interfere with utility lines.
Crown Raising
#crown-raising- The selective removal of lower branches to provide clearance for pedestrians, vehicles, lines of sight, or structures. Crown raising must maintain a minimum two-thirds live crown ratio to keep the tree healthy. Common along streets, driveways, and over walkways.
Structural Pruning
#structural-pruning- Pruning of young and developing trees to establish strong branch architecture: a single dominant central leader, well-spaced scaffold branches, and sound branch unions. Done early (every 2–3 years), structural pruning prevents the co-dominant stems and included-bark unions that cause storm failures decades later. The single most cost-effective tree-care investment.
Topping
#topping- The indiscriminate cutting of large branches back to stubs, leaving no lateral branches large enough to assume terminal-leader role. Topping is universally condemned by ISA-certified arborists: it causes decay at every stub, weak water-sprout regrowth, and structural failure within years. Tree Wise Men does not top trees under any circumstances.
Branch Collar
#branch-collar- The slightly swollen ridge of tissue where a branch meets a trunk or larger branch. Pruning cuts must be made just outside the branch collar to allow the tree to compartmentalize the wound and seal it over time. Cuts inside the collar (flush cuts) and cuts that leave stubs both cause decay and structural problems.
Credentials & Standards
5 terms
ISA Certified Arborist
#isa-certified-arborist- A tree-care professional who has passed the International Society of Arboriculture's comprehensive certification examination covering tree biology, diagnosis, pruning, safety, soil science, and urban forestry — and maintains certification through continuing education. The credential demonstrates verified knowledge of how trees grow, fail, and respond to care. Tree Wise Men employs 4 ISA Certified Arborists. Our ISA Certified Arborists
TCIA Accreditation(Tree Care Industry Association Accreditation)
#tcia-accreditation- A third-party verification by the Tree Care Industry Association that a company meets industry standards for safety practices, employee training, business ethics, insurance, and consumer protection. Fewer than 400 tree-care companies nationwide hold TCIA Accreditation — a fraction under 0.4% of the estimated 100,000+ U.S. tree-care companies. Tree Wise Men LLC is TCIA Accredited. What TCIA Accreditation means
TRAQ(Tree Risk Assessment Qualification)
#traq- An advanced ISA credential for arborists trained to systematically evaluate tree risk using a standardized methodology. TRAQ-qualified arborists assess the likelihood of structural failure, the part most likely to fail, the target (what would be hit), and the consequences. Used for formal written risk assessments, insurance documentation, and high-stakes decisions about trees near structures.
CTSP(Certified Treecare Safety Professional)
#ctsp- A safety credential from the Tree Care Industry Association for professionals who develop and oversee safety programs at tree-care companies. CTSPs are responsible for OSHA compliance, crew safety training, accident investigation, and safety culture. A CTSP on staff is one of the indicators TCIA Accreditation requires.
ANSI Z133
#ansi-z133- The American National Standards Institute's safety standard for arboriculture operations — the OSHA-recognized safety standard for tree care work. ANSI Z133 covers PPE requirements, electrical hazard distances, climbing systems, chainsaw operation, aerial lift use, and ground crew protocols. Tree Wise Men crews are trained to ANSI Z133 standards.
Treatments
4 terms
Propiconazole(Alamo)
#propiconazole- A systemic fungicide used in trunk injection to protect oak trees from oak wilt and elms from Dutch elm disease. Provides 1–2 years of protection per injection on healthy trees in known-infection areas. Most effective as a preventive measure; treatment success on already-infected red oaks is limited.
Emamectin Benzoate(TREE-äge, Arbor-Mectin)
#emamectin-benzoate- A systemic insecticide used in trunk injection to protect ash trees from emerald ash borer. Provides 2–3 years of protection per treatment on healthy ash trees with less than 30% canopy decline. Studies in Wisconsin and Michigan show 95%+ effectiveness. The optimal injection window is mid-April through June, when active transpiration distributes the insecticide.
Trunk Injection
#trunk-injection- A targeted treatment delivery method in which fungicides, insecticides, or nutrients are injected directly into a tree's vascular system through small ports in the trunk. Eliminates spray drift, protects beneficial insects and pollinators, and ensures the active ingredient reaches the canopy. Used for oak wilt, EAB, Dutch elm disease, and nutrient deficiencies.
Root Graft Barrier
#root-graft-barrier- A vibratory plow trench cut 4–5 feet deep between an infected oak and nearby healthy oaks to sever underground root grafts. Oaks of the same species growing within 50–100 feet of each other often form natural root connections through which oak wilt spreads. Severing the connection stops the underground spread to neighboring trees.
Equipment
4 terms
GRCS(Good Rigging Control System)
#grcs- A specialized rigging device used by professional arborists to lower large tree sections under controlled friction and mechanical advantage. The GRCS lets a single ground worker safely lower limbs that would otherwise require multiple workers or risk uncontrolled drops. Essential for technical removals near structures, vehicles, or lawns where uncontrolled falls aren't acceptable.
Grapple Saw Truck
#grapple-saw-truck- A truck-mounted hydraulic boom equipped with a grappling claw and integrated chainsaw. Operators grab, cut, and place tree sections directly from the truck cab without ground crew exposure under the work zone. Standard equipment for storm cleanup, hazardous removals near roadways, and large-tree work where ground access is constrained.
Spider Lift
#spider-lift- A compact tracked aerial work platform that fits through 36-inch gates and operates on uneven ground. Provides arborist access to canopy work on tight residential lots where a bucket truck cannot reach. Essential for isthmus and near-east Madison neighborhoods and similar urban density.
Stump Grinder
#stump-grinder- A self-propelled or towable machine with a rotating carbide-tipped wheel that chips a tree stump and surface roots into wood chips below grade. Tree Wise Men operates compact tracked grinders for tight residential lots and full-size grinders for estate properties, grinding 6–12+ inches below grade for replant-ready surface. Stump grinding services
Tree Anatomy
4 terms
Root Flare(root collar, trunk flare)
#root-flare- The wide base of a tree's trunk where it meets the root system. The root flare should be visible above the soil line. Buried root flares — common when trees are planted too deep or buried by mulch volcanoes — cause girdling roots, decay at the trunk base, and slow decline. Excavating a buried root flare is one of the highest-leverage tree-health interventions.
Drip Line
#drip-line- The imaginary line on the ground directly below the outermost edge of a tree's canopy. The drip line approximately marks the perimeter of the active root zone (though roots extend well beyond it). Construction tree-protection zones, mulch rings, and fertilization patterns all reference the drip line.
Included Bark
#included-bark- Bark trapped between two branches or stems where they grow tightly together, preventing the formation of a strong, fused branch union. Included-bark unions are mechanically weak and prone to splitting under wind or snow load. Common in silver maple, Bradford pear, and other co-dominant-stem species. Identifiable as a visible seam where two stems meet, often with bark turning inward.
Cambium
#cambium- The thin layer of actively dividing cells just under the bark that produces new wood (xylem) on the inside and new bark (phloem) on the outside. Damage to the cambium — from string-trimmer hits, deer rubbing, lawn mower strikes, or improper pruning — disrupts the tree's ability to move water and nutrients and is the entry point for most decay-causing organisms.
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