The Emerald Green Arborvitae (Thuja occidentalis ‘Smaragd’) is a highly favored selection in landscaping, particularly for creating dense, narrow privacy screens. A newly planted arborvitae is considered “established” when it has overcome transplant shock and developed a root system substantial enough to sustain its own needs. Establishment means the plant can draw sufficient water and nutrients from the native soil without relying on intensive supplemental care. At this point, the plant shifts its energy focus from survival to significant top growth.
Defining the Establishment Timeline
A newly planted Emerald Green Arborvitae typically requires between one and three full growing seasons to become fully established. This timeframe allows the root system to grow beyond the original root ball and integrate completely with the surrounding soil. The physiological process involves the plant diverting energy away from top growth, such as foliage and height, and prioritizing the expansion of its root mass.
Root development is the plant’s immediate biological goal, anchoring it and ensuring reliable water uptake. The first year is often entirely dedicated to this subterranean effort. Successful long-term establishment depends on this unseen growth below the soil line, even if the plant appears healthy above ground. Once the roots are fully integrated, the arborvitae transitions its energy back into noticeable vertical and lateral growth.
Factors Influencing Establishment Speed
Several environmental and pre-planting conditions determine whether the establishment period leans toward the shorter one-year mark or the longer three-year range. Smaller plants often establish faster than larger specimens because they have less foliage to support while roots are developing. The method of delivery also plays a role; container-grown trees typically experience less initial shock than those handled as balled and burlap (B&B), which may have had feeder roots severed.
The soil type and drainage are equally significant, as arborvitae require well-draining conditions to prevent root rot. Heavy clay soil retains excessive moisture, slowing establishment and potentially suffocating new root growth. A long, warm growing season provides more time for the plant to produce new roots, accelerating the overall timeline. Full sunlight exposure (six or more hours of direct sun daily) also supports the robust photosynthesis required to fuel root expansion.
Immediate Care for Successful Establishment
The most effective way to help an Emerald Green Arborvitae establish quickly is to provide consistent care immediately following planting to minimize transplant shock. The first step involves an initial deep watering to settle the soil around the root ball and remove air pockets. This saturation ensures the roots are in direct contact with the moisture-holding soil.
Consistent moisture management is necessary following the initial watering, often requiring water two or three times a week for the first few months, especially during dry or hot periods. Apply a two-to-three-inch layer of organic mulch, such as shredded bark or wood chips, around the base of the plant to regulate soil temperature and retain moisture. Keep the mulch ring several inches away from the trunk to prevent moisture accumulation against the bark, which could lead to rot. After the first few months, the watering frequency can be reduced to once weekly for the remainder of the first full growing season.