DALY: Allow Leyland cypress trees plenty of room for growth

One of the most widely planted trees in landscapes across Georgia is the Leyland cypress. It has many appealing qualities such as its pyramidal shape, attractive dark green foliage, and a rapid growth rate. The tree can be used to block unwanted views and enhance privacy. Despite its virtues, the plant frequently performs poorly in the landscape as a result of improper planting practices.

Leyland cypress trees can grow 50 to 70 feet high with a spread of 15 to 20 feet. However, they are usually planted too close together. The trees should be at least 10 feet apart, preferably 12 to 15 feet apart, and a minimum of 15 feet away from structures. Planting at this distance doesn't make them an effective screen for some time. However, they can grow four feet per year in height and two to three feet in width. In three to five years, they will be effective screens. If waiting a few years is not right for you, the trees can always be planted closer together with the understanding that every other one will eventually have to be removed. You can also plant other evergreen plants such as arborvitaes, Japanese cryptomerias, wax myrtles or certain hollies as an alternative to the Leyland cypress. They form effective and attractive screens.

Leyland cypress trees need to be planted in locations that receive full sun. Shade will reduce their vigor and cause the leaves and branches to thin out. The trees require fertile, well-drained soil. One of the most critical factors in the growth of a Leyland cypress is making sure they are watered properly. Both inadequate amounts and excessive amounts of water will cause them to suffer and decline.

A couple of stem canker diseases caused by a fungus can infect Leylands. The primary symptom is the foliage on the top or the lateral branches turning yellow or brown. The disease can potentially disfigure or kill the trees. The dry conditions of recent months have contributed to the development of these diseases. Since there are no effective chemicals for control, the best way to treat an infected tree is to prune out the dead branches. Cut below where the canker is on the branch. Make sure you sterilize the pruning tool in alcohol or bleach prior to making the next cut to prevent the spread of the disease. If trees have been extensively damaged or if the trunk itself is infected, they should be cut down. Also, during dry spells, make sure the trees receive the proper amount of water, which will reduce the likelihood of the disease developing.

Leyland cypress trees can be a great addition to the landscape if properly planted and maintained. However, this tree is rapidly becoming one of the most troublesome trees in Georgia. Due to improper planting and overuse, Leylands may go the way of plants such as the red tip photinia. This small tree was planted extensively in the 1970s and 80s as a hedge, but eventually a fungal leaf spot disease caused their demise.

Timothy Daly is an Agricultural and Natural Resource Extension Agent with Gwinnett County. He can be contacted at 678-377-4010 or tdaly@uga.edu.


RosieW 2 years, 5 months ago

Tim, I have seen some very effective plantings of leylands, but thousands of examples of improperly planted ones. There should be warning labels on the plant tags, in BOLD TYPE, spelling out their potential size. Example: neighbor next door planted about 1.5' off of the property line. We only have about 12' between our homes and the property line. The result would be that these conifers would grow up to 10' onto my property. The root competition severely limits other plantings other than shallowly rooted ground covers. Happy ending to my story is that they were all taken out two weeks ago by the new owners, at a very large but fair price.

Homeowner associations would be wise to add restrictive covenants re growing these. They do not make good neighbors as they are almost always planted way too close to the property line.


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