Q.Fertilizer Burn on Emerald Green Arborvitae
Last year, 2 Days after our garden beds were fertilized (liquid) by our tree service company, our arborvitae (and other trees etc) started turning brown. I called them and they said it was impossible for them to have fertilizer burn. Well, I am now faced with ripping out thousands of dollars and spending thousands more to replace them. I cannot tell if it is winter burn or fertilizer burn and if there is anything we can do to save them? Do we wait it out? Do we cut out the brown stems etc? Any advice?
There are other possibilities for the browning, search "emerald green arborvitae browning". Factors are your geographical location and climate, and soil and water management program. There pest and disease possibilities, "cypress tip miner" and Cercospora blight, a fungal disease. The consulting arborist can help sort this out. You will find pruning information in the recommended internet search, and/or from the consulting arborist.
It is not impossible that this is fertilizer burn, in fact it is quite likely. Chemical fertilizer with a high salt index can cause this, especially if applied with a high concentration tank mix and/or during a period of water deficit/drought stress. The high salts causes desication, drying out of the plant tissues. It appears from the photos that the plants are not dead but have some green foliage, therefore they will likely revive in time, with adequate water and regrowth. You can decide on your tolerance for waiting it out, or if that is not an option for you, then remove and replace.
A local consulting arborist, ISA Certified Arborist or ASCA Registered Arborist can provide site-specific assessment and recommendatons, including a written appraisal of plant values for a loss claim if needed.