Arborvitae is a plant that is widely used as an evergreen hedge or screen.
Some are suffering or completely dead.
What can be done?
In looking at local plantings of Arborvitaes this Spring, some seem to be partially or totally brown. I am often asked, will they recover.
Sadly, the answer is usually “NO”.
Why did this happen? The answers are not always conclusive. Too much water? Too little water?
Dr. Francesca Rotondo, who runs The Ohio State University C. Wayne Ellett Plant and Pest Diagnostic Clinic in Wooster Ohio received numerous samples of Arborvitaes last year (2024).
|
County |
Received on |
Diagnosis |
|
Cuyahoga |
9-Apr |
Pestalotiopsis mite eggs |
|
Cuyahoga |
9-Apr |
Pestalotiopsis needle blight, no detection for Phytophthora root rot |
|
Cuyahoga |
18-Apr |
Spider mites |
|
Cuyahoga |
15-Aug |
Pestalotiopsis needle blight, environmental stress |
|
Cuyahoga |
18-Aug |
Phyllosticta needle blight |
|
Delaware |
10-Oct |
Pestalotiopsis needle blight |
|
Erie |
11-Mar |
Pestalotiopsis needle blight, Phytophthora root rot not detected |
|
Erie |
21-Mar |
Pestalotiopsis needle blight |
|
Franklin |
4-Aug |
Environmental stress |
|
Franklin |
29-Apr |
Pestalotiopsis needle blight |
|
Franklin |
17-Jun |
Pestalotiopsis needle blight |
|
Franklin |
13-Aug |
Pestalotiopsis needle blight, environmental stress, mite eggs |
|
Franklin |
13-Aug |
Phyllosticta needle blight |
|
Franklin |
24-Apr |
Spider mites and Phyllosticta needle blight |
|
Franklin |
28-May |
Spider mites and Phyllosticta needle blight |
|
Franklin |
28-May |
Phyllosticta needle blight |
|
Franklin |
11-Jun |
Phyllosticta needle blight |
|
Fulton |
23-Jul |
Pestalotiopsis needle blight, spider mites , Phomopsis spp. on twigs |
|
Fulton |
27-Jul |
Phyllosticta needle blight |
|
Greene |
10-Oct |
Phyllosticta Needle Blight |
|
Greene |
29-Oct |
Phyllosticta tip blight |
|
Hamilton |
2-Dec |
Pestalotiopsis needle blight, environmental stress |
|
Hamilton |
11-Mar |
Pestalotiopsis needle blight |
|
Hamilton |
26-Aug |
Spider mites |
|
Licking |
10-Aug |
Environmental stress |
|
Licking |
15-Aug |
Environmental stress |
|
Licking |
18-Oct |
Phyllosticta Needle Blight |
|
Marietta |
15-Oct |
Pestalotiopsis needle blight, environmental stress |
|
Medina |
9-Apr |
Pestalotiopsis needle blight, no detection for Phytophthora root rot |
|
Medina |
25-Jul |
Environmental stress |
|
Medina |
30-Jul |
Environmental stress |
|
Miami |
19-Aug |
Pestalotiopsis needle blight, spider mites |
|
Montgomery |
18-Jan |
Possible Mites infestation |
|
Montgomery |
27-Jun |
Pestalotiopsis needle blight |
|
Montgomery |
14-Aug |
Phomopsis Needle Blight |
|
Montgomery |
29-Apr |
Phyllosticta Needle Blight and environmental stress |
|
Montgomery |
12-Apr |
Phyllosticta tip blight |
|
Richland |
11-Apr |
Pestalotiopsis needle blight |
|
Richland |
10-Jun |
Pestalotiopsis needle blight, environmental stress |
|
Franklin |
11-Jun |
Phyllosticta needle blight |
According to Bill Hendrick’s, previous owner of Klyn Nurseries and with 60 years of nursery experience notes “Arborvitaes need good moisture to grow and thrive. They can really suffer when put under drought stress.”
In a commercial nursery, irrigation can be managed.
Most nurseries have a grower assigned to a specific block of plants or someone who manages irrigation.
In the home landscape, watering many times becomes an afterthought. Even an irrigation system that is not monitored can even provide too much water.
Arborvitaes that are exposed to excessive water can suffer root rots and die.
Arborvitaes exposed to excessive winter winds while roots are frozen can desiccate.
Many times, Arborvitae that were closely cared for it the nursery are planted in the home or commercial landscape and not watered. This planting of arborvitaes was installed last summer in the middle of a drought.
There future survival is doubtful.
They were not irrigated like the were when grown in the nursery.
Last year (2024) was tough on even mature Arborvitaes. In northwest Ohio, late April and May where the soil was saturated. Then a full month or more of drought in Ohio, especially Southwest Ohio. Remember Arborvitaes are sensitive to drought stress. I believe we are seeing to results of last year’s extremes in weather.
Arborvitaes can suffer from other problems. Bagworms are becoming more of a problem in northern Ohio. They have been a problem for a number of years in Southern Ohio.
Bagworms
and Seasonal browning
is highlighted in the following post:
https://bygl.osu.edu/node/2272
These Arborvitea appear to be suffering from bagworm damage.
Scale can also attack Arborvitae:
A post on scouting for scale:
https://bygl.osu.edu/node/2272
Water seems to be a key to survival. Too much water and the roots cannot breathe, and the plant may rot.
Too little water and the plant will go into drought stress and may die.
The problem is most gardeners love to use Arborvitae as a screen.
Sometimes as a backdrop for other landscaping.
Possibly as a foundation planting in front of a building.
The screen may be used to hide a fence or an unwanted view.
The larger the arborvitaes, the harder to match the height when one dies.
A couple of things to remember when planting Arborvitaes. Make sure the site is well drain. Planting in a low spot is a good way to kill an Arborvitae.
Make sure you keep an eye on watering. When first planted, plants should be checked several times a week to insure adequate moisture.
During times of extreme drought, even established planting may require irrigation.
There are many different species of Arborvitae. Do your research on care and site requirements before you purchase and plant.
