What Is The Ideal Arborvitae Hedge Spacing? (Tree Spacing)
For a dense, single-row arborvitae hedge, set tree centers about 60–80% of the cultivar’s expected mature width apart. That means roughly 2–3 feet for ‘Emerald Green,’ 5–8 feet for ‘Green Giant,’ and 3–5 feet for ‘Techny.’ Choose the wider end for more air and access, and the closer end for faster screening.
The right spacing depends on the variety, not the size of the plant in its nursery pot. A small tree can grow into a broad evergreen, and tightly packed trees may look full at first but become crowded later. Before you buy, check the cultivar’s mature width and decide how quickly you want the row to fill in.
Choose Arborvitae Spacing by Cultivar, Mature Width, and Hedge Goal
Arborvitae spacing is the distance from the center of one trunk to the center of the next. There is no one ideal interval for every type. Use the cultivar’s expected mature width, your desired hedge density, and the space available to choose a practical distance.
A useful starting point for a dense, single-row hedge is 60–80% of the plant’s expected mature width. This is a design guide, not a universal horticultural rule. A closer interval can help a screen close sooner, while wider spacing leaves more room for airflow, access, and individual plant growth.
Typical spacing by cultivar
Mature widths vary with growing conditions and the source’s estimate, so check the plant label or a reliable nursery listing for the cultivar you are buying. The figures below are practical planning ranges, not promises that every plant will reach the same width.
| Arborvitae type | Typical mature width | Practical center-to-center spacing | Useful for |
|---|---|---|---|
| ‘Smaragd’ or ‘Emerald Green’ | About 3–4 ft | About 2–3 ft | Narrow privacy hedge |
| ‘Green Giant’ (‘Steeplechase’) | About 12–18 ft | About 5–8 ft | Large, fast-growing screen where space allows |
| ‘Techny’ | About 6–8 ft | About 3–5 ft | Medium-width hedge or screen |
These intervals are not interchangeable. For example, planting ‘Green Giant’ 2 feet apart does not make it a narrow hedge. It may make the row crowded as the trees grow. If your planting area is narrow, choose a cultivar with a narrower mature form instead of forcing a wide one into a small space.
Match spacing to the look and time you want
A dense screen usually calls for spacing near the lower end of the range. The foliage can meet sooner, but closer planting increases the chance of crowding later. A less formal screen or a row where you want access between plants can use wider spacing. Wider gaps may take longer to fill.
I use this simple planning question: “Would I still be comfortable with this distance when each tree is near its expected mature width?” If the answer is no, the spacing is likely too tight for your site or maintenance plan.
Also consider site conditions. Check the cultivar’s needs for sun and drainage, and make sure the row leaves room for future pruning and inspection. Locate utilities and confirm property boundaries before digging. A hedge that fits on planting day may become difficult to manage if its mature size is ignored.
Plan the number of trees
For a straight row, estimate the number of trees with this formula:
Number of plants ≈ hedge length ÷ spacing + 1
The “plus one” applies when you place a tree at both ends of the measured span. For example, a 40-foot row with 2.5-foot spacing works out to 40 ÷ 2.5 + 1 = 17 plants.
This is an estimate, not a substitute for laying out the actual row. End setbacks, corners, gates, and property-line limits can change the final count. Decide where the first and last trunk centers will sit, then measure the intervals between them before ordering.
Lay Out the Row and Plant at the Correct Depth
Good spacing starts with a clear row plan. Mark each tree’s trunk center before digging, then check the whole line for corners, gates, access, and end setbacks. When planting, use the root ball as your guide: the hole should be wider than the root ball, but not deeper than it.
Set and mark the planting line
First, identify the cultivar and confirm its mature width and height. Then mark a straight planting line with a string or another clear guide. Measure each interval from one trunk center to the next. Do not measure between pot edges or root-ball edges; those sizes can differ from plant to plant.
Set out the trees while they are still in their containers. This dry layout lets you check the spacing in context and shift the ends if needed. Leave room for gates, turns, and any planned access. If the row runs along a boundary, confirm where you are allowed to plant and how much room the mature trees will need.
Dig and set each tree
Dig each hole about 2–3 times as wide as the root ball and no deeper than the root ball. A hole that is too deep can leave the tree sitting too low after the soil settles. Set the root flare, where the trunk widens into the roots, at or slightly above the finished soil grade.
Backfill with the soil removed from the hole, then water thoroughly. Avoid burying the trunk. Apply mulch about 2–3 inches deep, but keep it clear of the trunk so it does not sit against the bark.
Spacing and planting depth solve different problems. Correct spacing gives the plants room to grow beside one another. Correct depth helps place the roots at the intended soil level. Neither makes up for poor drainage or a cultivar that is too large for the site.
Planning examples for common layouts
The examples below are planning scenarios, not reports from specific properties. They show how the same hedge length can call for different tree counts when the cultivar or goal changes.
| Layout scenario | Example spacing | Approximate count for a 40-ft span* | Planning note |
|---|---|---|---|
| Dense ‘Emerald Green’ row | 2.5 ft | 17 | Closer spacing can help the narrow plants meet sooner |
| ‘Techny’ hedge with more room | 4 ft | 11 | Leaves more room between plants than a tight layout |
| ‘Green Giant’ screen | 6 ft | 8 | Suits a larger cultivar better than very close spacing |
*Assumes a tree center at each end of the 40-foot span and equal intervals between centers. Adjust for setbacks and the positions of gates or corners.
These examples show why there is no single correct count per foot. A 40-foot row of ‘Emerald Green’ can need more than twice as many trees as a ‘Green Giant’ screen. The right choice depends on the cultivar and the space you can give it.
Watering, Pruning, and Ongoing Hedge Maintenance
Newly planted arborvitae need water while their roots establish, and they need attention during dry periods. Mulch helps cover the soil, but it should not touch the trunks. Prune only when appropriate for the cultivar and season, and avoid cutting into bare wood where the plant may not regrow.
Water and mulch after planting
Water each tree thoroughly after planting. During establishment and drought, water deeply and check the soil’s moisture rather than relying on a fixed schedule. The amount and frequency needed depend on local weather, soil, drainage, and the plant’s condition.
Keep mulch about 2–3 inches deep and away from the trunks. Mulch piled against a trunk can hold moisture against the bark. It also does not replace watering; check the soil beneath the mulch to judge whether the root area is dry.
Prune with the plant’s growth in mind
Pruning can help maintain a hedge shape, but it cannot safely shrink every cultivar to fit a space that is too small. Avoid cutting into bare wood where the plant may not regrow. If you are unsure how a particular arborvitae responds to pruning, check guidance for that cultivar before making large cuts.
Leave enough room to inspect and maintain the row. When plants are too close, it can be harder to reach the inner branches, check for problems, or work along the hedge. That is a practical reason to favor more space when access matters.
Seasonal Care and Diagnosing Crowding or Decline
Crowding often develops over time, so a hedge can look fine when young and still be poorly spaced for its mature size. Watch for thinning inside the row and limited access between plants. Check soil moisture and site conditions too, since spacing alone does not explain every decline.
Signs the row may be too tight
A tightly packed hedge may form a solid outer wall while foliage inside the row becomes shaded and thins or dies. Persistent crowding can also reduce airflow and make inspection and maintenance harder. These are reasons to plan for mature width rather than judging spacing only by how the young trees look.
If the trees are already planted, do not assume that pruning will solve the problem. First compare their cultivar and expected mature width with the available space. A wide-maturing tree planted too close may not be a good fit for the site even if you trim the outside.
What to do when the site is narrow
Do not try to solve a narrow planting area by placing a wide-maturing cultivar unusually close together. Choose a narrower cultivar, use a different screen design, or allow more space between trees and accept a longer wait for the gaps to fill.
Before planting, check mature width, utility locations, property lines, sunlight, drainage, and access. These checks can prevent a spacing choice that is hard to correct once the trees grow.
Conclusion: Choose Spacing Before You Buy
The best arborvitae hedge spacing comes from the cultivar’s expected mature width and the job you need the hedge to do. Start near 60–80% of mature width for a dense, single row, then adjust for airflow, access, and how quickly you want the screen to close. Mark trunk centers, confirm end positions, and avoid crowding a large cultivar into a narrow site.
Frequently Asked Questions
How far apart should arborvitae be planted for a hedge?
For a dense, single-row hedge, start with about 60–80% of the cultivar’s expected mature width. Common examples are 2–3 feet for ‘Emerald Green,’ 3–5 feet for ‘Techny,’ and 5–8 feet for ‘Green Giant.’
How far apart should Emerald Green arborvitae be?
‘Emerald Green,’ also called ‘Smaragd,’ is typically about 3–4 feet wide at maturity. A practical hedge spacing is about 2–3 feet from trunk center to trunk center.
How far apart should Green Giant arborvitae be?
A practical screen spacing for ‘Green Giant’ is commonly about 5–8 feet center to center. Use the wider end when you want more room and less crowding risk, and consider the cultivar’s large mature width before planting.
How far apart should Techny arborvitae be?
‘Techny’ is commonly about 6–8 feet wide at maturity. A practical planting interval is about 3–5 feet between trunk centers, adjusted for the site and the density you want.
Should arborvitae branches touch when planted?
No. Space trees by trunk centers rather than placing their pots or branches together. The foliage may meet as the trees grow, but planting them nearly touching can lead to crowding and make maintenance harder.
How many arborvitae do I need for a 40-foot hedge?
At 2.5-foot intervals, a 40-foot span needs about 17 plants if you place one tree center at each end. The count changes with spacing and end setbacks, so mark the first and last centers before ordering.
Does closer spacing make an arborvitae hedge fill in faster?
Closer spacing can help a hedge close sooner, but it also raises the risk of crowding as the trees mature. Choose an interval that balances the desired screening time with the cultivar’s mature width and the space available.
Do I measure arborvitae spacing from the trunk or the edge of the root ball?
Measure from trunk center to trunk center. Root balls and pots can differ in size, so measuring their edges will not give a consistent planting interval.
How wide should the planting holes be?
Make each hole about 2–3 times as wide as the root ball and no deeper than the root ball. Set the root flare at or slightly above the finished soil grade.
What if my yard is too narrow for the recommended spacing?
Choose a narrower cultivar or another screen design rather than crowding a wide-maturing arborvitae. Check the plant’s mature width and leave room for access and future care before you plant.
(This article was written by one of our staff writers, Evan Bradley. Visit our Meet the Team page.)
