Emerald Green Arborvitae (Thuja occidentalis ‘Smaragd’) is a popular evergreen for privacy hedges and screens. Understanding its unique root system is fundamental for ensuring these plants thrive and remain healthy for years, from initial planting to ongoing care.
Emerald Green Arborvitae Root System
Emerald Green Arborvitae have a shallow, fibrous root system. Unlike plants with a single, deep taproot, they develop a network of fine, delicate roots that spread out horizontally, rather than penetrating deeply into the soil. For a typical Emerald Green Arborvitae, the main root depth is generally around 6-8 inches. While some larger arborvitae varieties can extend their roots deeper, the ‘Smaragd’ cultivar maintains a more modest, shallow spread.
This fibrous structure means the plant primarily absorbs water and nutrients from the upper soil layers. The roots can spread horizontally, sometimes extending to the plant’s drip line, forming a wide but shallow base. This characteristic makes them non-aggressive toward nearby structures, as their roots are not strong enough to cause damage.
Factors Influencing Root Growth and Health
Several environmental conditions significantly impact the development and health of Emerald Green Arborvitae’s shallow root system. Soil type plays a crucial role; well-draining soil is essential for healthy root spread, preventing issues from excessive moisture. Conversely, compacted or waterlogged soils can suffocate roots and lead to decline. These arborvitae thrive in moist, well-drained loams with a neutral to alkaline pH, though they can tolerate various soil compositions like sand, clay, or chalk, provided drainage is adequate.
Watering practices also heavily influence root development. Consistent, deep watering encourages roots to grow outwards and establish a more extensive system. Frequent, shallow watering keeps roots confined to the uppermost soil layers, making them more susceptible to drought stress. Proper drainage is critical, as poor drainage is a common cause of root rot, which can quickly compromise the plant’s health.
Planting and Care for Healthy Roots
Proper planting techniques are critical for supporting the shallow root system of Emerald Green Arborvitae. Position the top of the root ball level with or slightly above the surrounding soil grade. Planting too deeply can lead to stem rot and hinder the plant’s ability to thrive. The planting hole should be dug two to three times wider than the root ball, but no deeper than its height, allowing space for horizontal root expansion. Gently loosen any pot-bound roots before placement to encourage them to spread.
After planting, thoroughly water the plant to settle the soil and eliminate air pockets. Consistent watering is vital, especially during the first growing season, to establish an extensive root system. Aim for deep watering sessions, particularly during dry periods, to ensure moisture reaches the shallow root zone without waterlogging the soil.
Applying a 2-4 inch layer of organic mulch, such as wood chips or bark, around the base of the plant is very beneficial. Keep the mulch a few inches away from the trunk to prevent moisture buildup and potential rot; this layer helps conserve soil moisture, regulate temperature, and protect surface roots. When planting near structures, maintaining a distance of 3-4 feet is advisable to allow for the plant’s mature width and facilitate proper air circulation and maintenance.