Q: I have two holly trees at my front door that are in desperate need of pruning. I didn’t have it done in spring because of the flowers, and now there are berries. When can I trim these?
A: That’s one of those Catch-22 dilemmas if your goal is berries. If you prune in winter or spring, you’ll cut off the buds that would’ve produced the flowers that ultimately lead to the fall fruits. If you wait until after the flowers drop, you’ll cut off the ovaries that have been pollinated.
One strategy is to reduce size by thinning out or shortening only the longest branches. If you let at least some of the branches alone, you’ll get berries on the ends of those. Wait until the flowers are almost done to prune because then you can be sure to let behind at least some of the wood that will fruit. That’s the advantage of pruning selectively with hand pruners.
If you’re shearing, though, you’ll be cutting the ends off of all or most of the branches. Depending on how far back you go, it’s very possible you’ll cut off all flowers and berries.
Some people have it both ways by shearing or pruning heavily one year and then letting their hollies alone as much as possible the following year. That way you get a good fruiting at least every other year.
If the berries aren’t a concern, you can prune any time from the end of winter through early summer. The worst time would be fall when the hollies are heading into dormancy. You don’t want to encourage any new growth then that won’t harden off in time to keep from browning over winter.