These white cedars, Thuja occidentalis, have had the lower 2/3 of their growth cut off, a practice known as “limbing up.” This practice, when performed on evergreens, never really looks good and is something to be avoided whenever possible. These homeowners didn’t, sadly, giving us another Bad Pruning to learn from.
The lesson, in short: don’t cut a living branch completely off an evergreen tree for aesthetic reasons.
Why is this the rule for evergreens? It has to do with these trees’ natural shape, and how they store energy and grow. Evergreen trees don’t have the well-placed extra buds and food reserves that deciduous trees do. They therefore rarely regrow where they were pruned back hard, such as back to the trunk or the ground. Limbing them gets you a plant with stilt-legs and knobby knees.
Evergreen trees also usually have a pyramidal or columnar shape. These look more natural and richer when they go to the ground. The exception to the rule is this: If your evergreen is weeping (such as weeping blue atlas cedar) or irregular (like cedar-of-Lebanon), you can probably limb it up and be okay. Limbs won’t regrow but, done tastefully; it won’t look starkly unnatural.
A newly planted tree is one occasion when you might want to take off a limb. When a new tree is brought home from the nursery, it may have a few branches that are overlapping or growing right next to each other. This tends to happen more often when trees are young, so the removal of such branches is acceptable. This means that another branch will still be growing in that area.
Alternatives To Limbing Up
- Prune back lightly. Cutting back much less of a younger branch to a node won’t make the tree look as bare, and healthy regrowth is likely. The younger you start this kind of intervention on the lower limbs, the better.
- Kill a blocking tree and plant a more suitable species. Evergreen “screen trees” like red cedar, white cedar (arborvitae), and Leyland cypress are very widely available in large sizes and narrow forms and grow fairly quickly. It may feel expensive especially if you need to hire labor to plant them (consider trying to plant them yourself instead), but the weeping once over the money is better than weeping forever over the eyesore.
- Ask: “Do I have to?” The homeowner in this photo didn’t. You can see that the left one is not blocking a window view. The right one had its right side shorn for the window—not a great practice, but so be it—but there was still no need to limb it up for a view.
- When you have to: If a limb is diseased or seriously damaged. If you need to be able to see through the tree or create walking clearance for safety reasons, then don’t expect it ever to look good. Evergreen trees were not made to be “limbed up.”
- Choose the season: For most evergreen trees, the best time to prune is when branches are not actively growing. This will make it much easier to avoid additional damage to tree bark, and the likelihood of an unwanted fungal disease goes way down by choosing a slow time of year. Thus, the best time to prune evergreens is from late winter to early spring, well before any new growth will take off for the new season.