I just planted Leyland cypress trees; they came in plastic, about 1 foot long, and they were in a dormant stage. I planted them exactly per instructions given, but now most of them are turning completely brown. Are they going through a stage of dormancy or are they dying?
The Gardener’s Answer
Hello, Sally: Leyland cypress (Cupressocyparis leylandii) are fast-growing evergreens that thrive when planted in full sun, at least six hours each day, and demand well-drained soil. Root rot can become a problem if the plants are exposed to excessive moisture. These evergreens do have their share of problems, including bagworms and various fungal diseases. It is normal that evergreens shed some of their inner foliage. This is especially true for the Leyland cypress because they are such fast growers that they need to drop some of their foliage in order to make room for new growth. If all of the needles have turned brown and are falling off, I am sorry to say that it does not sound good for your cypress. Unfortunately, once they have turned brown there is nothing we can do to help save them. When evergreens turn brown this does not indicate a dormant stage. During the winter when the growth slows down is when they are dormant but they always remain green. This is true for all evergreen plants. They usually do not put on any new growth at this stage. I cannot say for sure what has happened to your newly planted evergreens without seeing them, but you can take a sample to your County Cooperative Extension Service for a positive diagnosis. This way you will know if they were not healthy when you purchased them or if it was a watering issue. You can also contact the nursery that you purchased them from to see about their guarantee policy. For now, you can go ahead and remove the plants because dead plant material is a great environment for insects and disease to live.