Thuja green tree dry/disease?? - Ask Extension
Few thuja trees planted this march were dying really well until 3-4 weeks where they turned brown and leaf got ‘crispy, and fell
Knowledgebase
Thuja green tree dry/disease?? #879662
Asked July 31, 2024, 8:25 PM EDT
Few thuja trees planted this march were dying really well until 3-4 weeks where they turned brown and leaf got ‘crispy, and fell
Anne Arundel County Maryland
Expert Response
When a trees and shrubs fail within the first couple of years of installation it is usually not due to insects or disease but abiotic/non-living factors- most often from a problem with planting, mulching or watering.
You can learn about abiotic issues here:
https://extension.umd.edu/resource/what-causes-trees-and-shrubs-die/
In this case, the most likely cause is heat and drought stress coupled with inadequate watering. It has been intensely hot and very dry for long stretches in central Maryland this season and your new shrubs have little in the way of roots.
We can tell you did some watering as the grass around it is green, but that grass also competes for the water.
A ring of mulch (no deeper than 3 inches and kept pulled back from contact with the trunk can help keep the ground more cool and moist.
We notice that there are no weeds nearby- can we rule out that any weed killer herbicides were used? Some can kill other plants when they are applied over the roots of non-target plants, or drift from the location they were applied.
We are not sure that your arborvitae can recover but to give them their best chance, mulch them and follow our best watering instructions:
https://extension.umd.edu/resource/watering-trees-and-shrubs/
Christine
You can learn about abiotic issues here:
https://extension.umd.edu/resource/what-causes-trees-and-shrubs-die/
In this case, the most likely cause is heat and drought stress coupled with inadequate watering. It has been intensely hot and very dry for long stretches in central Maryland this season and your new shrubs have little in the way of roots.
We can tell you did some watering as the grass around it is green, but that grass also competes for the water.
A ring of mulch (no deeper than 3 inches and kept pulled back from contact with the trunk can help keep the ground more cool and moist.
We notice that there are no weeds nearby- can we rule out that any weed killer herbicides were used? Some can kill other plants when they are applied over the roots of non-target plants, or drift from the location they were applied.
We are not sure that your arborvitae can recover but to give them their best chance, mulch them and follow our best watering instructions:
https://extension.umd.edu/resource/watering-trees-and-shrubs/
Christine
