The ‘Emerald Green Arborvitae’ is a narrow evergreen appreciated for its dense foliage and natural pyramidal shape. These trees typically mature to a height of 10 to 15 feet with a width of about three to four feet, making them ideal for screening in smaller spaces. Determining the correct distance between each trunk is the single most important decision for ensuring the long-term health, density, and aesthetic success of the planting.
Spacing for Privacy Hedges vs. Specimen Plants
The required distance between plants depends on the gardener’s goal, which is usually either to create a solid, continuous privacy hedge or to showcase individual specimen trees. When planning a dense privacy screen, the objective is for the mature trees to eventually touch and merge, forming an opaque wall of foliage. For this purpose, arborvitae should be planted on a tighter center-to-center spacing, typically three to four feet apart.
This narrower planting distance encourages the trees to grow together quickly, achieving the desired visual barrier. However, this closeness necessitates careful consideration of air circulation, as overly tight planting can trap moisture and increase the risk of fungal diseases. While some growers suggest spacing as close as two feet, the three to four-foot range offers a better balance between achieving a quick screen and maintaining adequate airflow for long-term health.
Conversely, if the goal is to highlight the natural, symmetrical conical form of an individual ‘Emerald Green’ tree, a wider spacing is necessary. Specimen plants should be spaced further apart to allow each tree to reach its full, unhindered mature width of three to four feet. Planting these accent trees at a distance of five to six feet apart from center to center ensures they have sufficient room to develop their classic shape without competing for sunlight, water, or nutrients. This wider spacing prevents overcrowding, which can otherwise lead to lower branch dieback and an overall sparser appearance at the base of the tree.
Preparing the Planting Site
Once the appropriate spacing has been marked, preparing the planting site is the next critical step for successful establishment. The planting hole should be excavated two to three times the width of the root ball to give the roots plenty of loosened soil into which they can expand. While the hole must be wide, it should be no deeper than the height of the root ball itself.
It is important to position the tree so the top of the root ball is level with or slightly above the surrounding grade. Planting too deep is a common error that can cause the trunk flare to sit below the soil line, leading to the suffocation of roots and root rot. Before placing the tree into the prepared hole, the root ball should be gently inspected. Any circling or matted roots should be teased apart or scored to encourage outward growth into the native soil.
When backfilling the hole, use the native soil that was removed, avoiding the use of heavy amendments which can create a distinct soil boundary that roots hesitate to cross. As the soil is returned, it should be tamped gently by hand or watered in thoroughly to eliminate any large air pockets that could dry out and damage the fine root hairs. The final step of site preparation is confirming that the tree stands straight and the root crown is properly exposed above the soil line.
Ensuring Establishment: Immediate Care
Immediate and consistent care following planting is paramount for the arborvitae to establish a robust root system in its new location. The newly planted tree must receive a deep, thorough watering immediately after the backfilling process is complete. This first soaking settles the soil around the roots and ensures that the entire root ball is saturated before the tree can begin absorbing nutrients.
During the first growing season, especially the first few months, a clear watering schedule is necessary to prevent the sensitive roots from drying out. Young arborvitae require regular moisture, often needing water once or twice weekly depending on local climate and rainfall. Monitoring the soil moisture a few inches down is the best way to determine if the tree needs water.
Applying a two to three-inch layer of organic mulch, such as shredded bark, helps to regulate soil temperature and conserve moisture by reducing evaporation. However, the mulch must be kept several inches away from the trunk of the tree, creating a “mulch donut” rather than a “mulch volcano”. This deliberate gap prevents moisture from accumulating directly against the bark, which is a common trigger for fungal infections and insect issues at the base of the plant.