Topping an arborvitae, meaning cutting off the central leader or shearing the top off to reduce height, is physically possible but almost always a mistake. Unlike many deciduous trees and shrubs, arborvitae (genus Thuja) do not regenerate foliage from bare, old wood. Once you cut into leafless interior branches, what you expose stays exposed: a flat-topped stub surrounded by brown, dead-looking wood that the tree has no biological mechanism to cover back up. The result is usually permanent disfigurement rather than a compact, shorter tree.
How Arborvitae Actually Grow
Arborvitae produce their new growth only at the tips of existing green branches. Their foliage grows in flat, fan-like sprays, and the green portion of each branch extends only a short distance back from the tips. Behind that green zone, the interior wood is bare. This is a fundamental trait of the species, not something that changes with feeding or watering. A healthy arborvitae that has never been pruned will often have a dense, dark interior with no living foliage at all, which is perfectly normal for the tree but a serious problem if you start cutting into it.
This growth habit is the core reason topping fails. When you remove the top of the tree, you cut through the green growth zone and expose interior wood that has no dormant buds capable of pushing new foliage. Deciduous trees and some broadleaf evergreens can sprout new shoots from latent buds hidden under bark, which is why you can sometimes pollard a maple or hedge a privet and watch it fill back in. Arborvitae lack that ability. The spot where you made the cut stays bare, and the tree’s natural conical shape is gone for good.
What a Topped Arborvitae Actually Looks Like
People who top arborvitae usually expect the tree to simply grow back shorter and denser. What happens instead is a flat or ragged top with visible brown stubs, sometimes described as looking like the tree was broken in a storm. The remaining foliage below the cut may continue growing outward, which can make the tree look lopsided or mushroom-shaped rather than pyramidal. Over the following seasons, the damaged top does not fill in. Some people try to correct this by topping again, which only makes the bare zone larger.
If the tree was topped severely, removing a third or more of its height, the damage is not just cosmetic. The sudden loss of that much foliage disrupts the tree’s ability to feed itself through photosynthesis. Research on trees subjected to major above-ground removal shows that the resulting imbalance between root mass and remaining leaf area leads to root mortality and depleted energy reserves, with trees that fail to rebuild leaf area quickly facing especially poor prospects for recovery.
The Underground Consequences
The visible damage from topping gets all the attention, but the below-ground effects can be just as serious. When a large portion of the canopy is removed, the root system suddenly has far more tissue to maintain than the remaining foliage can support. In clonally regenerating trees, research has shown that poor regrowth of leaf area after above-ground disturbance leads to extensive root death and reduced carbohydrate reserves, weakening the tree’s ability to grow the following year.1Journal of Ecology. Leaf area renewal, root retention and carbohydrate reserves in a clonal tree species following above‐ground disturbance
The energy dynamics make intuitive sense once you think about it. A tree’s roots depend on sugars produced by the leaves. When you remove a large chunk of the canopy, the roots are the last part of the tree to receive replenished energy supplies. Studies on mature trees have found that after significant defoliation, branch-level energy reserves can bounce back within a single growing season, but roots may take up to two years to recover. During that window, the root system is vulnerable to decline and the tree is at greater risk of dying.2Trees. Defoliation increases risk of carbon starvation in root systems of mature aspen Arborvitae are in an even worse position than the deciduous species studied, because they cannot rapidly regenerate new leaf area the way a tree that sprouts from latent buds can. The energy deficit lingers.
A stressed root system also makes the tree more susceptible to drought and disease. Arborvitae are already somewhat shallow-rooted, and losing root mass after a severe topping can tip a tree that was doing fine into visible decline: browning foliage, dieback of remaining branches, and eventually death over a period of one to several years.
Light Trimming Versus Severe Topping
There is a meaningful difference between topping and light maintenance pruning. Shearing the outermost few inches of green growth from an arborvitae’s top and sides is routine and generally well-tolerated. This is how arborvitae hedges are maintained, and it works because you are only cutting within the green zone, leaving the tips’ ability to regenerate intact. The key rule: never cut back farther than the green foliage extends. If you can see brown wood, you have gone too far.
Trimming the very tip of the leader by a few inches can slow upward growth modestly and is not the same as topping. Some growers pinch or lightly cut the terminal leader in spring to encourage slightly denser growth at the crown. This is a gentle technique that removes weeks’ worth of new growth, not feet of established canopy. It is nothing like the dramatic height reduction most people mean when they say they want to “top” a tree.
The trouble is that most homeowners considering topping are not trying to remove a few inches. They are looking at a 15-foot arborvitae that they wish were 8 feet tall, and no amount of careful pruning will make that work. Removing several feet of height means cutting deep into old wood, which is irreversible on an arborvitae.
Why People Want to Top and What to Do Instead
The urge to top usually comes from one of a few situations: the tree has outgrown the space it was planted in, it is blocking a view or window, it is crowding a structure, or a row of arborvitae used as a privacy screen has become too tall. Each of these problems has a better solution than topping.
- Wrong cultivar: Many topping situations trace back to planting a cultivar that naturally grows much taller than the space allows. ‘Green Giant’ arborvitae, one of the most popular varieties sold at garden centers, routinely reaches 40 to 60 feet at maturity. Planting it where you need a 6-foot screen was always going to end badly. Dwarf and semi-dwarf cultivars like ‘Emerald Green’ (also sold as ‘Smaragd’), ‘North Pole,’ or ‘Holmstrup’ top out at 10 to 15 feet and are far better choices for residential settings.
- Blocking a window: If just one or two branches are intruding, you can selectively prune individual branches back to a lateral branch that still has green foliage. This reduces the tree’s profile in one direction without destroying the top. It is time-consuming and requires some care, but it preserves the tree’s shape.
- Privacy screen too tall: If a row of arborvitae has exceeded the desired height by a modest amount, annual shearing of just the new growth each spring can hold them at roughly their current height for years. This only works if you start before the trees significantly exceed your target height. If they are already many feet past it, shearing the tips will not bring them down.
- Replacement: When the tree is simply too big for its spot and there is no way to manage it through selective pruning, removal and replacement with an appropriately sized cultivar is often the most practical long-term answer. It feels drastic, but it ends the annual battle and gives you a tree that actually fits the space.
Choosing the right cultivar at planting time is by far the easiest way to avoid the topping question entirely. Reading the mature height on the nursery tag is not optional. A tree described as growing 40 feet tall will, in fact, grow 40 feet tall.
Can an Already-Topped Arborvitae Be Saved?
If you or a previous homeowner already topped an arborvitae, the honest answer is that the damage is permanent in terms of the tree’s natural shape. The flat, bare top will not fill in. However, the tree may still be alive and reasonably healthy below the cut line, and you have a few options for living with it.
One approach is to let the remaining lateral branches near the top grow upward over time. Without the central leader, one or sometimes two side branches will attempt to take over as the new leader. This process is slow and the result is never as symmetrical as the original tree, but after several years the crown may look less obviously damaged. You can encourage this by gently tying or staking a strong side branch upward, training it into a more vertical position.
Another option, if the tree is part of a hedge row, is to shear the remaining green growth into a flat-topped or slightly rounded hedge shape and maintain it at that height going forward. A deliberately flat-topped formal hedge reads as intentional in a way that a single topped tree does not. This only works if all the trees in the row are at a similar height.
If the topping was severe and the tree is showing signs of stress like widespread browning, dieback in the remaining canopy, or branch tips that fail to put out new growth in spring, the tree may be in irreversible decline. At that point, watering deeply during dry spells and avoiding any further pruning is about all you can do. Adding fertilizer to a severely stressed tree is generally not helpful and can actually worsen the problem by pushing growth the weakened root system cannot support.
Timing and Pruning Cuts That Arborvitae Tolerate
For the kinds of light pruning arborvitae do tolerate, timing matters. The best window is late spring to early summer, after the new growth flush has emerged but before it hardens off. Cutting during this period lets the tree seal over wounds while still actively growing. Pruning in late summer or fall is riskier because the fresh cuts may not harden before winter, leaving the tree vulnerable to cold damage and desiccation.
When removing individual branches, cut back to a junction with another living branch rather than leaving a stub. Stubs on arborvitae do not sprout new growth; they simply die back and can become entry points for fungal disease. A clean cut at a branch junction lets the tree compartmentalize the wound more effectively.
One common mistake is shearing arborvitae into a narrow column by removing all lateral growth. This looks tidy at first but creates a tree with an extremely thin shell of green foliage over a hollow interior. Any heavy snow, ice, or wind event can then splay the branches open, and the interior bare wood is suddenly visible with no way to cover it. A slight taper, wider at the base and narrower at the top, is both more natural-looking and structurally stronger. It also allows light to reach lower branches, keeping them alive and green rather than letting the bottom of the tree go bare.
The Snow and Ice Factor
Arborvitae are famously vulnerable to snow and ice damage, and this intersects with the topping question in a way people do not always anticipate. An intact arborvitae with a conical shape sheds snow reasonably well, with the pointed top deflecting accumulation outward. A topped arborvitae with a flat crown collects snow on that flat surface, adding weight exactly where the tree has been weakened. Heavy snow loads on a topped arborvitae are more likely to split branches apart or cause further breakage at the already-damaged top.
In regions with heavy winter precipitation, a topped arborvitae may need to be physically tied or wrapped with burlap or twine each fall to prevent splaying. This is labor-intensive and not particularly attractive, and it is an ongoing annual commitment that the topping was supposed to eliminate in the first place. Intact arborvitae in the same conditions rarely need wrapping unless they are multi-stemmed varieties prone to splaying on their own.
Arborvitae Versus Other Evergreens You Can Top
Part of the confusion around topping arborvitae comes from the fact that some other common evergreens do tolerate heavy pruning. Yew (Taxus) is the classic example: you can cut a yew back to bare wood, even to stumps, and it will regenerate vigorously from dormant buds. Holly and boxwood also resprout from old wood, which is why they work as formal hedges that can be cut hard periodically. If you have had success drastically cutting back a yew hedge, it is understandable to assume arborvitae would behave the same way. They do not.
Most conifers share arborvitae’s limitation to varying degrees. Pine, spruce, and fir all struggle to regenerate from cuts into old, needleless wood. Among the common landscape conifers, yew is the notable exception. Hemlock (Tsuga) can sometimes recover from moderate hard pruning, but it is not nearly as reliable as yew. If you need a tall evergreen screen that you can cut hard and have it recover, yew is the genus to choose, not Thuja.
When Professionals Top Arborvitae Anyway
Despite everything above, some landscapers and tree services will top arborvitae if a client insists. Occasionally this is done as a desperation measure to save a tree from removal, under the reasoning that a disfigured tree still provides more screening than no tree at all. In commercial landscape maintenance, rows of arborvitae along property boundaries are sometimes mechanically sheared at a set height year after year, which can amount to repeated light topping if the trees keep trying to push past the shear line. This works only when the shearing is done frequently enough that the cut never goes past the green zone, essentially holding the tree at its current height rather than reducing it.
Some property owners also top arborvitae to comply with local height ordinances or neighbor disputes about blocked light. In those cases, the practical question shifts from “is this good for the tree?” to “is this less bad than removing it entirely?” If keeping the tree matters and the required height reduction is modest, a trained arborist may be able to reduce height through selective thinning cuts rather than a flat-topped shearing. This is skilled, time-consuming work that costs more than running a hedge trimmer across the top, but it preserves more of the tree’s natural look and does less damage. Finding an ISA-certified arborist, rather than a general lawn service, is worth the effort if you go this route.