dying arborvitae - Ask Extension
Help figuring out why these trees are dying. There is a group of four above a swale that are dying and a group of 3 below the swale are growing just ...
Knowledgebase
dying arborvitae #889268
Asked November 03, 2024, 1:44 PM EST
Help figuring out why these trees are dying. There is a group of four above a swale that are dying and a group of 3 below the swale are growing just fine. All planted at the same time. I'm hesitant to plant new trees until i know what has happened to these.
Howard County Maryland
Expert Response
The last couple of growing seasons have been difficult on our landscape plants. There were long periods of concerning drought, then a very wet spring followed by intense and prolonged periods of heat and drought. It has taken a toll on even established trees but newer trees are showing serious dieback, especially if they were not irrigated during the periods of drought.
We expect that the trees on the upper area of the swale didn't get the water they needed to establish well and thrive.
They look like they may be Green Giant Arborvitae, which hail from cooler climates- they can grow well here (and have the added advantage of being deer resistant) but do best when temps are lower (60s to 70s and soil is moist and well-drained).
The ones at the base of the swale may get a little less sun too.
How long ago were they planted and how were they cared for afterwards? Monitoring for water needs for the first 24 months in the ground is critical for good establishment.
They look very closely spaced. If/when you replant, we suggest spreading them out and planning for their eventual size.
We'd also recommend using a variety of plants so that if one type has a problem you won't lose the whole area.
Our privacy screening page explains more:
https://extension.umd.edu/resource/plants-mixed-privacy-screens/
Christine
We expect that the trees on the upper area of the swale didn't get the water they needed to establish well and thrive.
They look like they may be Green Giant Arborvitae, which hail from cooler climates- they can grow well here (and have the added advantage of being deer resistant) but do best when temps are lower (60s to 70s and soil is moist and well-drained).
The ones at the base of the swale may get a little less sun too.
How long ago were they planted and how were they cared for afterwards? Monitoring for water needs for the first 24 months in the ground is critical for good establishment.
They look very closely spaced. If/when you replant, we suggest spreading them out and planning for their eventual size.
We'd also recommend using a variety of plants so that if one type has a problem you won't lose the whole area.
Our privacy screening page explains more:
https://extension.umd.edu/resource/plants-mixed-privacy-screens/
Christine
