Boxwood roots run shallow and wide
Established boxwood, especially the older English varieties common on Belle Meade's original estate plantings, holds most of its root mass in the top several inches of soil, spread out well beyond the width of the visible shrub. That's very different from a tree's root structure, and it means a stump sitting what looks like a safe distance from a hedge can still have boxwood roots running directly underneath it. We check for this by hand before grinding starts, working a small area by shovel near the hedge line rather than assuming the visible gap between stump and shrub tells the whole story underground.
Vibration is as much a risk as direct contact
A grinder doesn't have to touch a hedge to stress it - the vibration transmitted through packed soil during a long grind can disturb shallow boxwood roots enough to set a plant back, especially older, slower-growing specimens that don't recover from root disturbance the way a younger plant would. On jobs where a stump sits close to a hedge we consider worth protecting, we work in shorter passes with pauses between them rather than one continuous grind, giving the ground - and the roots in it - less sustained vibration to absorb at once.
A slower approach costs time, not money on your end
Working around an established hedge line takes longer than grinding the same stump in open lawn, sometimes considerably longer if the boxwood in question is old and irreplaceable on any reasonable timeline. That extra time is a cost we build into how we schedule the appointment rather than a surcharge added to the invoice - the price reflects the stump's size and the site's overall complexity, decided upfront, not billed by the hour as we go.
Signs we watch for after the fact
Boxwood stress from a nearby disturbance doesn't always show immediately - sometimes a section starts bronzing or thinning weeks after the work, once the plant's had time to react to root disturbance it experienced during the grind. If that happens after a job we did, we'd rather hear about it and talk through what's possible than have you wonder whether it's connected to the stump work at all.
The short version
Boxwood's shallow, wide-spreading roots and low tolerance for vibration mean a stump near a hedge line needs a slower, hand-checked approach, planned into the schedule rather than rushed to save time.