Trimming the bottom of an arborvitae is physically easy but almost always a bad idea, because the bare area left behind will not fill back in. Arborvitae belong to the genus Thuja, a group of evergreen conifers that share a frustrating trait: they do not produce new growth from old, leafless wood. Once you cut away those lower branches, you are left with a permanent gap between the ground and the remaining foliage, and no amount of waiting or fertilizing will close it. Understanding why this happens, and what you can do instead, saves a lot of regret.
Why Arborvitae Cannot Regrow Lower Branches
The core issue is how arborvitae generate new foliage. Growth happens at the tips of existing green branches, where active buds sit. The older interior and lower wood gradually loses its ability to produce buds as it becomes shaded by the canopy above. Once a section of branch has gone bare and turned brown, the dormant buds that might have reactivated have long since died. Cut that branch off, and there is nothing left to sprout from.
This is different from many deciduous shrubs and a handful of conifers that can push new shoots from latent buds hidden under bark. Yews, for example, are one of the few conifers that can be cut back hard and still recover. Arborvitae cannot do this. If you shear one back to bare wood on the sides or bottom, those sections stay bare. The tree is not dead, it simply has no mechanism for replacing what was removed from old wood.
What Causes Bare or Thin Bottoms in the First Place
Readers searching this question usually have an arborvitae that already looks leggy or scraggly at the base, and they are wondering whether trimming it up into a cleaner shape would help. Before reaching for the pruners, it helps to know what caused the thinning, because the cause shapes the solution.
- Shade from above: As arborvitae grow taller, the upper canopy blocks light from reaching the lower branches. Without adequate sunlight, those lower branches thin out and eventually die. This is the most common cause and is essentially inevitable in mature, unpruned specimens.
- Crowded spacing: Arborvitae planted in hedgerows too close together shade each other’s sides and bottoms even faster. The interior and lower portions lose foliage within a few years once neighboring trees close the gaps.
- Animal browsing: Deer find arborvitae foliage highly palatable, especially in winter when other food sources are scarce. A single season of heavy deer browsing can strip the lower branches clean up to the height a deer can reach, roughly four to five feet.
- Snow and ice loading: Heavy wet snow can bend or snap lower branches, creating gaps. Repeated seasons of snow damage compound the problem because arborvitae cannot replace what is broken off.
- Age and natural form: Some arborvitae cultivars naturally lift their skirts as they mature, developing a more tree-like form with a visible trunk. This is genetic, not a sign of poor health.
Each of these causes has a different management strategy, but none of them is solved by cutting away the bottom branches. Removing them just makes the gap official and permanent.
When Trimming the Bottom Might Make Sense
There are a few narrow situations where cleaning up the base of an arborvitae is reasonable, as long as you accept the result will be permanent. If the bottom branches are already dead, brown, and unsightly, removing them tidies the appearance and eliminates a haven for fungal growth and pests. Dead wood does not serve the tree, and cutting it away does no harm. The distinction is between removing dead wood (fine) and removing live green growth in hopes it will regenerate (it will not).
Some homeowners deliberately limb up a large arborvitae to create a small tree form, exposing the trunk and planting shade-tolerant groundcover beneath. This can look attractive with mature specimens that have developed a thick, interesting trunk, though it fundamentally changes the character of the plant from a dense screen to an ornamental tree. If privacy screening is the goal, this defeats the purpose.
Another scenario: when lower branches are dragging on the ground, trapping moisture against the trunk and encouraging rot or fungal disease. Removing the lowest few inches of branch contact with the soil is preventive maintenance rather than aesthetic pruning, and it barely changes the look of the tree.
How to Properly Prune Arborvitae Without Ruining Them
The golden rule is to never cut back into bare wood. Always leave green foliage on every branch you prune. If you follow this rule, you can shape arborvitae quite aggressively and they will fill in nicely.
For routine maintenance, the best approach is light shearing of the outer shell once or twice a year, ideally in late spring after new growth has started to emerge but before it has fully hardened. This encourages denser branching at the tips without exposing old wood. You can remove up to about a third of the current season’s new growth without stressing the plant.
If you want to reduce the overall size, do so gradually over two or three years rather than all at once. Take a few inches off the top and sides each season. Arborvitae respond well to this kind of incremental shaping because new growth keeps covering the cuts. The mistake people make is waiting until the tree is dramatically overgrown and then trying to hack it back to the desired size in one session, which inevitably exposes bare wood.
Timing matters. Late spring through early summer is the best window. Avoid pruning in late summer or fall, because the new growth stimulated by pruning may not harden off before cold weather arrives, making it vulnerable to winter damage. Winter pruning is also risky because the open cuts are slow to heal in dormancy and can desiccate in cold, dry wind.
Strategies for Hiding a Bare Bottom
If your arborvitae already has a thin or bare lower section and you want to restore the appearance of a full screen, the most practical options do not involve pruning at all.
Planting a shorter evergreen in front of the bare zone is the most common fix. Boxwood, low-growing yews, dwarf hollies, or compact junipers can fill the gap without competing too aggressively for light. Choose something that stays at or below the height of the bare zone so it visually bridges the gap between the ground and the remaining arborvitae foliage. This layered look can actually end up more attractive than a plain arborvitae hedge.
Another approach is to gently pull lower branches downward and tie them loosely to stakes or the trunk, encouraging them to fill in gaps below where they currently sit. This only works if there is still live green growth on the lower portions, just angled upward rather than outward. Over a season or two, the redirected branches may close some of the thin spots.
For deer damage specifically, the long-term solution is fencing or deer repellent rather than trying to repair the browsed zone. If the foliage was eaten within the last year and some green branch stubs remain, there is a chance those stubs will push new tip growth. But if the branches were stripped to bare wood, they are done.
Arborvitae Varieties and Their Bottom Growth Habits
Not all arborvitae cultivars behave the same way at the base, and choosing the right variety for your situation can prevent the problem entirely.
‘Emerald Green’ (also sold as ‘Smaragd’) is one of the most popular cultivars and tends to hold its foliage relatively well all the way to the ground, especially in full sun. Its narrow, columnar form means the upper canopy does not shade the lower branches as heavily as wider varieties. However, when planted in shade or spaced too closely, even ‘Emerald Green’ will thin at the bottom over time.
‘Green Giant’ is a fast-growing hybrid that can reach 40 to 60 feet tall. Its rapid upward growth means the lower branches lose light quickly, and mature specimens almost always have some bare trunk showing at the base. If you plant ‘Green Giant’ expecting a full-to-the-ground screen forever, you will likely be disappointed within 10 to 15 years.
Globe arborvitae varieties (‘Woodwardii,’ ‘Little Giant,’ ‘Hetz Midget’) stay compact and round, and rarely develop bare bottoms because their shape allows light to reach all sides. They are not useful as tall screens, but if the goal is a low border or foundation planting, they sidestep the legginess issue entirely.
Eastern white cedar (Thuja occidentalis) cultivars as a group tend to hold their lower foliage better than Western red cedar (Thuja plicata) cultivars, partly because the eastern species grows more slowly and stays denser. If you are planting a new hedge and bottom fullness matters to you, pay attention to the species and cultivar rather than just grabbing whatever is cheapest at the nursery.
The Role of Sunlight and Spacing
More than any other factor, light determines how long an arborvitae keeps its lower foliage. Arborvitae are full-sun plants. They tolerate partial shade, but the trade-off is thinner growth, especially on the shaded side and at the bottom. A hedge planted along a north-facing fence line or under the canopy of large deciduous trees will thin at the base much faster than one in full sun.
Spacing is the other critical variable. The instinct when planting a privacy hedge is to pack the trees close together for immediate coverage. This works beautifully for the first few years, but as the trees grow, they shade each other out internally. A hedge of ‘Emerald Green’ arborvitae spaced three feet apart will look fantastic at year three and bare-bottomed at year eight. Spacing them four to five feet apart delays that process considerably, even though the hedge takes a year or two longer to fill in initially.
If you already have a tightly spaced hedge that is thinning, selectively removing every other tree can sometimes rejuvenate the remaining ones by letting light back in. This feels counterintuitive when you planted the hedge for density, but the trees that remain will often flush new growth on their lower sides within a season or two once they have light again. This only works if there is still some green foliage on the lower branches. Once they have gone completely bare, even full sun will not bring them back.
Fertilizing and Watering After Pruning
If you do prune your arborvitae, helping the tree recover efficiently means supporting new growth with adequate water and nutrients. Arborvitae are not heavy feeders, but a balanced slow-release granular fertilizer applied in early spring gives them the resources to push new tip growth after shearing. Avoid fertilizing in late summer or fall for the same reason you avoid late pruning: you do not want to stimulate tender growth right before winter.
Watering is more important than fertilizing for recovery. Arborvitae are shallow-rooted and suffer in dry conditions, especially during the first year or two after planting and after heavy pruning. A stressed, drought-affected arborvitae will not put out vigorous new growth no matter how much you prune it. Deep watering once a week during dry spells, rather than light daily sprinkles, encourages roots to grow deeper and makes the tree more resilient overall.
Mulching around the base with two to three inches of wood chips or shredded bark helps retain soil moisture and moderates root-zone temperature. Keep mulch a few inches away from the trunk itself to avoid creating a moist environment against the bark, which can invite disease.
When Replacement Is the Better Option
Sometimes the honest answer is that the arborvitae is too far gone to save its appearance through pruning or companion planting. If the bottom half of the tree is completely bare, the interior is hollow, and the remaining foliage at the top is thin and ragged, you are fighting a losing battle. Replacing the tree with a new, appropriately sized cultivar and learning from the spacing and variety mistakes of the first planting is often more satisfying and less expensive than years of creative camouflage.
Removing a large arborvitae is straightforward compared to many other trees. The root system is shallow and fibrous, so stump grinding or even manual removal is usually manageable. The wood is soft and lightweight, making cleanup easier than with hardwood species. If you are replacing a whole hedge, doing it in stages (removing alternating trees and planting replacements) can maintain some screening during the transition, though the mismatched heights will look awkward for a few years.
For anyone planting fresh, the takeaway from all of this is simple: give arborvitae full sun, appropriate spacing for the mature size of your chosen cultivar, and light annual pruning from the beginning. A well-maintained arborvitae that has been lightly sheared every year since planting will hold its foliage to the ground for decades. The trees that end up bare and leggy are almost always the ones that were planted too close, in too much shade, or left completely unpruned until they were already overgrown.