Seasonal Action Guide
When to Trim Boxwood and Evergreen Hedges
The short answer
For boxwood, do your main shaping shear in early June, after the spring flush of growth has hardened off; a second light touch-up in July is fine. Thinning — reaching in and removing whole small branches to let light and air into the center — is best done in the dormant months, December through February. Thinning matters as much as shearing: it keeps the interior alive and helps prevent disease.
Avoid trimming evergreen hedges in late summer or fall. Cutting then forces tender new growth that won't harden before frost and gets killed back, and it can leave the plant weak going into winter.
The two jobs and their timing
- 1Thinning — December to February — In the dormant season, remove entire small stems here and there to open the interior to light and air. This is the healthiest way to prune boxwood.
- 2Shearing — early June — Do the main formal shear in early June once the spring flush has firmed up, with an optional light second shearing in July.
- 3Avoid — late summer and fall — Don't shear late in the season; the tender regrowth won't harden before frost and will be damaged or killed.
✔ Thinning (removing whole branches to the point of attachment) keeps a boxwood healthier than repeated hard shearing, which shades out and kills the interior over time.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- University of Maryland Extension — Boxwood: Identify and Manage Common Problems — Thin boxwood (remove whole stems to open the interior) from December through February, and do main shearing in early June after the spring flush hardens off, with an optional light second pruning in July; avoid late-season cuts.
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