Hi, I am hoping you can help me regarding my trees. In April we planted thirty 15' emerald green arbs to provide a natural privacy fence to a landscape design. Not knowing any better, my husband fertilized the trees to help them along, as one of the trees was looking like it was struggling. Now all of them look dull and some have some brown on the outside. Is there anything we can do to save these trees?? Thank you!

While the industry typically suggests no fertilizer the first year, your description does not suggest that there is/was a connection to their current condition. Depending on how many times the Arbs were root pruned or transplanted during production, there was substantial root loss when dug and planted in your yard. this limited root system will struggle to supply all the needles with moisture to keep hydrated. Conditions like full sun, partial shade, exposure, soil types all have a role in how quickly a plant will recover. A general rule is there is a year of recover for every inch of trunk diameter. For that period of time, plants are in your care to ensure full recovery. A 15' tall Arb likely has a trunk diameter (or trunks) 2 1/2 or more. If there is a warranty involved with this planting, contact the nursery and alert them to their condition and follow any suggestions given. Take pictures for your records.