ISA Prescriptive Pruning Qualified (PPQ)
The most rigorous pruning qualification in arboriculture — designed to eliminate the gap between industry standards and what actually happens to your trees.
The Problem PPQ Was Built to Solve
Pruning malpractice — lion-tailing, excessive thinning, topping, ignoring structural defects — is widespread across the industry. And it rarely comes from malicious intent. It comes from vague, incomplete pruning prescriptions that leave too much decision-making to whoever happens to be holding the saw.
The ANSI A300 Standard is a performance standard, not a work specification. It tells arborists what the finished result should achieve — but it doesn't replace the need for precise, written instructions before work begins. PPQ was developed specifically to bridge that gap.
What It Is
Prescription Pruning Qualification is an advanced, post-certification credential — available only to ISA Certified Arborists. It was developed by Dr. Edward F. Gilman, PhD (professor emeritus, University of Florida) alongside a committee of leading consulting arborists, municipal foresters, and arboriculture researchers. It is not a beginner's course. It is built for practitioners who take the science of pruning seriously.
The vision behind PPQ is direct: no tree — or group of trees — should ever be pruned without a prescription. Earning this qualification means an arborist has demonstrated the ability to create defensible, written pruning plans that align client goals with tree biology — before a single cut is made.
ANSI A300 Is Our Baseline. PPQ Goes Further.
Most arborists who reference ANSI A300 compliance use it as a shorthand — a signal of intent, not a detailed plan. A300 tells you what to achieve. PPQ teaches you how to specify it in writing so that the outcome is consistent, measurable, and reproducible regardless of who does the work.
PPQ also adopts the A300-2023 shift away from the rigid "25% rule" toward objective-based pruning — where each tree's species, vigor, and health guide the prescription, not an arbitrary percentage. The result is more precise, more defensible, and genuinely better for the long-term health of the tree.
What This Means for Your Trees
- ✓Every pruning recommendation starts with a written, defensible prescription — not field improvisation or vague contract language.
- ✓We use objective-based pruning informed by each tree's specific species, vigor, and health — not a blanket percentage cut.
- ✓Our approach aligns your goals and your tree's biological conditions into a unified plan before any crew touches it.
- ✓You get the same quality of precision on every visit — because the prescription is written, not assumed.
- ✓This is a rare, post-CA advanced qualification. Very few practicing arborists in the country hold it.