How to Water Emerald Green Arborvitae
Thuja occidentalis 'Emerald Green'
Reviewed by Kiersten Rankel M.S.
Quick Answer
Water newly planted Arborvitae deeply 2 to 3 times per week for the first 6 to 8 weeks. After it is established, deep-soak every 10–14 days from May through September.
The goal is a few deep soaks that wet the entire root zone, never a daily sprinkle. Year one is when most losses happen.
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How Often and How Much to Water
Adjust the sliders below for your pot size, light, and setting. The numbers assume a well-draining loam or amended planting hole and a site with drainage.
Setting
Every
9days
Use
1cup
Your Watering Rhythm Across the Year
Soil dries faster in the growing season, which varies by region. Slow down watering in the off-season to avoid overwatering.
Pacific
Mountain
Midwest
Northeast
Southeast
JFMAMJJASOND
Growing season
Growing season
9days
Resting season
3–4weeks
How to Water Your Emerald Green Arborvitae
Soak deeply, drain fully. Arborvitae sends roots down 12 to 18 inches over time, and the watering pattern in year one shapes how deep those roots go.
1
Pour slowly at the base of the trunk in a wide ring out to the dripline. A soaker hose or slow drip works better than a sprinkler.
2
Soak until water has reached at least 12 inches deep. Stick a screwdriver into the soil to test, it should slide in easily through the wet zone.
3
Water in the morning so the foliage dries by night. Damp inner foliage overnight invites needle fungus.
4
Add 2 to 3 inches of mulch out to the dripline but keep it 3 inches off the trunk. Mulch holds moisture between waterings.
Should You Water Your Emerald Green Arborvitae Today?
Always check the soil before you water. Established Arborvitae handle a long dry stretch better than soggy roots, and the most common cause of bronzing is overwatering, not under.
Hold off
Soil 6 inches down still feels damp
Inner foliage looks bright green
New tips firm and uniform
No yellow or brown patches inside the canopy
Recent rain in the last week or two
Ready for water
Soil 6 inches down dry and crumbly
Outer foliage looking dull or grayish
New tips wilting in the afternoon sun
It has been over 2 weeks since rain or watering
Soil pulls back from the trunk leaving a small gap
If Something Looks Off
Underwater and overwater can both turn an Arborvitae bronze. The soil moisture, the pattern of damage, and the timeline tell them apart.
Underwatered
Soil
Bone-dry 6 inches down and pulled back from the trunk
Leaves
Outer foliage browns from the tips inward and the damage spreads slowly
Pace
Slow decline that stabilizes within a week of a deep soak
Next steps
Run a slow soaker hose at the dripline for 30 to 60 minutes
Check by pushing a screwdriver into the soil to confirm it has reached 12 inches deep
Repeat once a week for 3 weeks even if it rains lightly
Existing brown foliage won't green back up but new growth in spring fills in. Do not trim brown sections until you see fresh green in the same branch
Overwatered
Soil
Stays soggy a week after watering with mossy or mushroom growth at the base
Stem
Bark softening or weeping near the soil line
Leaves
Inner foliage yellows and browns from the lower part of the tree upward
Pace
Steady decline that worsens through wet weeks even after you stop watering
Next steps
Stop watering immediately and pull mulch back 6 inches from the trunk
If the planting hole sits in standing water, score drainage channels away from the tree
For container Arborvitae, repot in fresh well-draining mix in a clean pot
Wait at least 2 weeks before watering again and only after the top 6 inches go dry
Remove any branches that have died back to bare wood once the tree stabilizes
Got More Questions?
How often do newly planted Arborvitae need water in the first year?
For the first 6 to 8 weeks plan on 2 to 3 deep waterings per week, more if the weather is hot and dry. Each watering should soak the rootball thoroughly.
After that taper to once a week through the rest of the first growing season, then once every 10 to 14 days in summer of year two. By year three the tree is usually self-sufficient outside of long droughts.
Why is my Arborvitae turning brown on the inside?
Some inner browning is normal, especially in fall when the tree sheds older needles. Heavy inner browning that spreads outward is usually root stress, often from too much water or compacted soil that holds water around the roots.
Check soil drainage by digging a small test hole nearby and watering it. If water stands for over an hour, the site is too wet. Improve drainage and ease back on supplemental watering.
Should I water my Arborvitae in winter?
In zones with mild winters where the ground doesn't freeze, give it a deep soak once a month if there has been no significant rain. Evergreens lose water through their needles all winter and a dry root zone before a freeze causes winter burn.
In zones with frozen ground, stop watering after the ground freezes and resume in spring once it thaws.
Can I plant Arborvitae too close together for hedging?
Spacing affects watering more than people realize. Plants set 2 feet apart compete for water and need a soaker hose run longer than spaced plantings.
For Emerald Green specifically, 3 feet between trees is the standard hedge spacing. Tighter than that and expect to water more often the first 2 years.
How long can my Arborvitae go without water if I'm on vacation?
Established Arborvitae handle 3 to 4 weeks easily in mild summer weather. In a hot dry stretch, deep-soak before you leave and ask a neighbor to run the soaker for an hour at the 2 week mark.
Newly planted Arborvitae in their first year cannot safely go more than a week without water in summer. Set up a timer or have someone check.
Should I fertilize while I'm correcting an Arborvitae watering problem?
No. A struggling tree cannot use the fertilizer and feeding stressed roots makes the problem worse.
Get the watering and drainage right first. Wait until you see fresh green growth on the tips, then apply a slow-release evergreen fertilizer in early spring. Skip fall and winter feeding entirely.
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About This Article
Kiersten Rankel M.S.
Botanical Data Lead at Greg · Plant Scientist
Editorial Process
Watering guidance verified against Thuja occidentalis 'Emerald Green' growth data from Greg's botanical database, cross-referenced with USDA hardiness zone data and published horticultural research.
0+ Greg users growing this plant
USDA hardiness zones 2a–7b