Since boxwoods are evergreen, it’s tempting to think you can prune them whenever you have a free slot in your calendar. Maybe you’re thinking of tackling it in the fall once the busy summer garden chores have wound down? Hold that thought! While the actual trimming is easy enough, your boxwood might pay a steep price later on.
The Great Pruning Debate
If you spend any time browsing garden blogs or magazines, you’ll see a lot of conflicting advice about fall pruning. Some folks say it’s a hard “no,” while others think the entire autumn season is fair game—even though the gold standard for pruning is usually between April and mid-September. You could certainly experiment and see what happens, but you’d be risking permanent damage to your plants. If you want to play it safe, it’s better to stick to a different schedule.
Why Fall Pruning Can Be Risky
The main issue is that autumn weather is totally unpredictable. One day it’s sunny, the next it’s pouring, and a surprise frost is always lurking around the corner. Just because a late prune worked out one year doesn’t mean you’ll get lucky the next. Here’s why experts generally advise against a late fall trim:
- Warm spells can trigger new growth that isn’t ready for winter.
- Fresh shoots don’t have enough time to “harden off” before the cold hits.
- It leaves the plant vulnerable to frost damage.
- Wet, rainy fall days create the perfect breeding ground for fungal diseases.
Some gardeners have even observed that a radical “hard prune” in the fall can prevent the boxwood from budding at all when spring rolls around.
When Fall Pruning is Necessary: Disease Control
There is one major exception: if your boxwood is showing signs of disease, like boxwood rust, you shouldn’t wait. In this case, grab your shears immediately to try and save the plant. If you leave an infected plant alone until spring, the infection might take over completely.
Tips for a Successful Fall Trim
If you absolutely must prune your boxwood in the fall, timing is everything. Pick a dry, overcast day. You should never prune in the rain or under the scorching direct sun. If the weather takes a turn—either a deep freeze or an unseasonably hot spell—be ready to protect your boxwood with garden fleece to prevent sunburn or frostbite.
Better Times to Prune
For boxwood hedges, edging, or simple geometric shapes, July is usually the sweet spot. One good trim then is often all you need. If you’re maintaining more intricate topiary shapes, you can lightly prune every four to six weeks from April through mid-September.
Quick Tip:
Always use sharp, sanitized shears for a clean cut. I also recommend laying down a tarp or drop cloth first—it makes cleaning up those tiny clippings a whole lot easier!
