Green Giant Arborvitae are popular choices for creating natural privacy screens or landscape accents due to their rapid growth and dense foliage. Proper watering, especially after planting, is crucial for their successful establishment and long-term vitality. Understanding hydration practices ensures a robust root system and overall plant health.
Initial Watering Schedule
Immediately after planting, Green Giant Arborvitae require consistent and deep watering to help them settle into their new environment and minimize transplant shock. For the first two weeks, water every other day, ensuring the root ball is thoroughly saturated.
Following the first two weeks, adjust the watering frequency to every three days for the subsequent two weeks. Keep the soil around the root ball consistently moist, but not waterlogged. Supply about 2 gallons of water per tree at each watering, allowing for slow absorption.
After the first month, the frequency shifts to once or twice a week, depending on weather conditions. For the entire first growing season, newly planted Green Giants need about one inch of water per week, from rainfall or irrigation. This consistent moisture supports the development of a strong root system.
How to Determine Watering Needs
Reliance on a fixed watering schedule may not be ideal, as actual water needs can vary. A practical method to assess soil moisture is the “finger test.” Insert a finger two to three inches into the soil near the base of the tree; if it feels dry at this depth, watering is likely needed.
Another effective tool for precise moisture assessment is a moisture meter. By inserting the probe into the root ball, the meter provides a reading indicating the moisture level from dry to wet. Water when the meter shows a drier reading, allowing the soil to cycle from wet to slightly dry, which promotes healthy root development.
Observing the soil surface also provides clues; pale, gray, or cracked soil indicates dryness. Checking the soil moisture six to eight inches deep, just outside the root ball, helps ensure water reaches deeper roots and not just the surface. This prevents shallow root growth, making the tree more vulnerable to drought.
Factors Affecting Watering Frequency
Several environmental and site-specific conditions influence how often a newly planted Green Giant Arborvitae needs water. Soil type plays a role; sandy soils drain quickly and may require more frequent watering. Clay soils retain moisture longer, potentially necessitating less frequent but careful watering to prevent waterlogging and root issues.
Sun exposure and temperature also impact water evaporation rates. Trees in full sun or during periods of high temperatures (above 80 degrees Fahrenheit) will dry out faster and need more water. Conversely, cooler temperatures or partial shade can reduce the need for frequent irrigation. Wind can also accelerate moisture loss from both the foliage and the soil, increasing water requirements.
The size of the Green Giant Arborvitae at planting can affect its initial water demands. Larger trees, having a more extensive root ball to establish, may initially require more consistent hydration than smaller specimens.
Recognizing Watering Issues
Green Giant Arborvitae exhibit specific signs when receiving too much or too little water. Underwatering often manifests as wilting or curling leaves, browning tips, and dry, brittle foliage. The entire tree or specific branches might gray out or turn brown, indicating severe dehydration.
Conversely, overwatering can lead to yellowing leaves, especially at the base of the tree, and stunted growth. The foliage may appear green but become fragile and break easily. Overly wet soil deprives roots of oxygen, potentially leading to root rot, which causes wilting and browning. If the soil around the tree remains constantly wet and muddy, it indicates overwatering or poor drainage.
Watering Established Green Giants
Once Green Giant Arborvitae are fully established, typically after one to two years, their watering needs significantly decrease. Established trees are more drought-tolerant and can often rely on natural rainfall for sufficient moisture. During prolonged dry spells or periods of extreme heat, supplemental watering may still be beneficial to maintain their vigor.
For established plants, the focus shifts to less frequent but deep watering. This encourages the root system to grow deeper into the soil, seeking out moisture and enhancing the tree’s resilience to dry conditions. Providing one inch of water per week, from rain or irrigation, is generally adequate for established trees during dry periods. Mulching around the base of the tree can help conserve soil moisture and reduce the frequency of watering needed.