Yes, you can technically top an arborvitae, but the practice carries real risk — it often leaves permanent bare spots and distorted form, especially on mature trees, so selective pruning is the safer route for height control.
A row of arborvitae that has outgrown its space is a common dilemma. The temptation is to grab the saw and level the tops at the height you want. One wrong cut, though, and that lush green privacy screen can turn into a row of stubs with dead brown centers that never fill back in. Arborvitae do not regrow from old bare wood the way many broadleaf shrubs do, so the decision to top them deserves a careful look at what actually happens afterward.
What Happens When You Top An Arborvitae?
Topping an arborvitae removes the terminal leader and most of the active foliage at the crown. Unlike many deciduous trees that respond by sending out new shoots from the cut, arborvitae rely on green needles attached to live wood for regrowth. Once you cut back into older, leafless stems, those branches typically stay bare. The result is a tree with a flat top of dead stubs and live growth only on the lower, untouched sides.
This is not just cosmetic. The tree loses a significant portion of its photosynthetic capacity at the top, which stresses it during hot summers or drought periods. Stressed trees become more vulnerable to pests like bagworms and diseases such as needle blight.
Does The Top Grow Back After Cutting?
Generally, no — at least not in the way you probably hope. An arborvitae’s central leader is the primary upright growing point. Once removed, the tree rarely replaces it with a single new leader. Instead, side branches near the cut may try to turn upward, but they seldom regain a natural conical shape. The top remains flat or develops multiple competing leaders that look awkward and may split under snow or wind load.
Young, fast-growing arborvitae have a better chance of pushing new growth from just below the cut if you leave some green needles on the remaining stem. On mature trees, however, the odds of a nice recovery are poor.
When Is Topping Acceptable?
There are a few situations where topping makes sense:
- Young trees being trained for a hedge: Light heading cuts on vigorous young plants can encourage denser branching at the top, as long as you leave green foliage on the stubs.
- Emergency height reduction: A storm-damaged leader or a tree threatening a power line may force a hard cut. In this case, accept the visual result and monitor the tree for health afterward.
- Gradual size control over several years: Spreading a large height reduction across 2–3 years reduces shock and gives side growth a chance to fill in between cuts.
For most routine height maintenance, selective pruning — shortening individual branches back to a side branch — is far safer than shearing across the whole top.
How To Top An Arborvitae The Right Way
If you decide to proceed, timing and technique matter. Follow these steps to minimize damage:
- Wait until late winter or early spring. Prune just before new growth begins — typically late February through March for most U.S. zones. This gives the tree the entire growing season to respond.
- Remove no more than one-third of the total height in a single year. Taking off more stresses the tree and increases the chance of dead stubs.
- Make reduction cuts to a side branch. Instead of cutting straight across the top, find a sturdy side branch at your target height and cut back to just above it. This preserves some foliage and a more natural profile.
- Do not seal the cuts. Arborvitae heal on their own. Tar or wound paint traps moisture and encourages rot.
- Clean your tools between cuts if you are pruning multiple trees — this prevents spreading disease from one plant to another.
Arborvitae Pruning: Topping Versus Selective Pruning
| Pruning Method | Best For | Risks |
|---|---|---|
| Topping (cutting straight across) | Young hedge training, emergency reduction | Permanent bare spots, distorted form, stress, no regrowth on old wood |
| Selective pruning (branch-by-branch) | Mature trees, height and width control | Slower process, takes more planning |
| Light shearing (trimming tips only) | Formal hedge maintenance, green tips | Builds a dense outer shell but can create a hollow interior over time |
| Crown reduction (removing leader only) | Reducing overall height while preserving shape | Multiple leaders may form; acceptable on young trees |
| Hard pruning (cutting into old wood) | Not recommended except for severely damaged trees | Very high risk of permanent dead zones, dieback, or tree loss |
The Fine Gardening guide on pruning arborvitae covers branch-by-branch reduction cuts in more detail and stresses that keeping some green needles on each cut branch is the key to regrowth.
Common Mistakes That Kill Arborvitae After Topping
- Cutting back to leafless brown wood. If there are no green needles left on the stub, that branch is done. It will not regrow.
- Removing too much at once. Taking off half the tree in one season creates a shock the root system cannot support.
- Topping in summer. Heat stress plus foliage loss can be fatal. Late winter pruning avoids this.
- Expecting a boxy hedge after topping. Arborvitae do not fill in evenly across a flat cut the way yew or boxwood do — you get an unnatural flat top with sparse growth.
- Topping old trees expecting lateral branching. Removing the terminal bud on a mature conifer does not force dense side growth the way it does on a maple or oak. The tree simply stops growing upward at that point and the cut remains visible.
What To Do Instead Of Topping
If your arborvitae has simply grown too tall for its location, the best long-term solution is to replace it with a shorter variety suited to the space. That is not always practical for an established hedge, though. In that case, a multi-year selective reduction plan works best: shorten the tallest leaders by one-third this year, let the tree respond, then reduce again the following year. Side branches will begin to fill upward over time, and you retain a natural-looking tree rather than a flat-topped stub.
For privacy screens that are getting too wide, thin out interior branches rather than shearing the entire side. This improves air circulation and light penetration while keeping the foliage layer healthy.
Living With The Results Of Topping
If you have already topped an arborvitae and are wondering what to do now, the answer is mostly patience. Keep the tree watered during dry spells — a stressed tree with reduced foliage needs consistent moisture. Remove any dead branches that appear, but resist the urge to apply fertilizer, which can push weak, floppy growth. Over the next 1–2 years, the remaining side branches may fill upward somewhat, but the top will likely never regain a natural taper. Plan on replacing the tree if the appearance matters to you.
References & Sources
- Fine Gardening. “How to Prune an Arborvitae That’s Too Tall or Wide.” Detailed project guide on selective reduction cuts vs. topping.