A modelled range is only as useful as your understanding of where it breaks down. These are the conditions under which the figures above will be wrong, published so you can cite them honestly or discount them appropriately.
—Species matters more than these size bands capture. Bamboo, wisteria, and established ivy involve root systems that behave nothing like a comparably sized juniper, and can run several times the tabled figure.
—Soil conditions swing extraction cost significantly. Heavy clay, rocky ground, or roots grown into a foundation, drain, or retaining wall convert a straightforward pull into hand excavation.
—Disposal is excluded from most rows and is not trivial. Root balls carry soil, which makes shrub waste heavy as well as bulky, and some green-waste facilities surcharge or refuse soil-laden loads.
—Toxic species carry handling premiums that are not modelled here. Oleander, yew, poison ivy, and giant hogweed require protective equipment and separate disposal streams.
—Hedge linear-foot pricing assumes reasonable access along the run. A hedge against a wall or fence can only be worked from one side, which slows extraction considerably.