ATHENS – Leyland cypress is one of the most commonly planted landscape trees, but poor site selection and disease pressure could soon send them down the path of red tips and Bradford pears.
Popular as a hedge and in new landscaping, trees should be planted at least 10 to 15 feet apart, as the rapid growth of trees will require thinning after a few years to keep them from crossing each other and reduce necessary air circulation. in the canopy to prevent disease.
“Leyland cypress trees are one of the most commonly planted trees in the landscape,” said Tim Daly, a cooperative extension officer at the University of Georgia in Gwinnett County. “They are popular because of their rapid growth and their ability to provide a screen against traffic areas or neighbors.”
The Leyland cypress (X Cupressocyparis leylandii) is a hybrid species resulting from a cross between the false Nootka cypress (Chamaecyparis nootkantensis) and the Monterey cypress (Cupressocyparis macrocarpa). It was discovered on a British estate in the late 1800s, Daly said.
Poor site selection can create problems with Leyland cypress trees.
“They grow in tall trees, and in some parts of the world, they can grow to 100 feet tall and almost 50 feet wide,” Daly said. “Think about the damage a tree this size could cause to your house, fence, or driveway just a few feet away. “
It can be hard to imagine a tiny Leyland Cypress growing into a tree 100 feet tall, but with proper care it can and will happen, he said. Leyland cypress trees grow about 4 feet per year in height and 2 to 3 feet in width.
They need full sun all day.
“The shade will reduce their vigor, causing them to thin out and become more susceptible to disease,” Daly said. “They also need a lot of air circulation inside the canopy to dry out the branches and leaves.”
Planting too close to a fence, building, or each other will keep tree interiors from drying out, he said, and could lead to fungal disease.
The tree is best suited to fertile, well-drained soils.
“The amount of water in the soil is one of the most critical factors in the growth of Leyland cypress,” Daly said. “Too much water will increase rotting fungal diseases of the roots, and too little water will lead to stress and, ultimately, diseases of the stems and leaves.”
To monitor soil moisture, use a shovel to open a 4-inch-deep space in the soil near the base of the trees. Smell the soil and test it for moisture. If it is dry, water. If it gets wet, avoid watering.
Diseases can wreak havoc on Leyland cypress trees.
“The use of chemical control is not feasible because the application is ineffective and will have no effect on the control,” said Daly. “Severely infected trees may need to be removed. “
Red-tipped photinias are small trees that were widely used in the 1980s as a hedge. Most plants succumbed to Entomosporium leaf spot fungal disease. Bradford pears, although not seriously ill, have fast-growing soft wood and sloping forks. This makes the branches easy to separate.
Several Leyland cypress substitutes are available, including:
– Holly like the “Nellie R. Stevens” and “Emily Bruner” varieties. These are best for borders in full sun.
– Arbovitaes (Thuja occidentalis), in particular the cultivar “Green Giant”, which was selected as a gold medalist plant from Georgia in 2007.
– Wax myrtles (Myrica cerifera) grow quickly in full sun.
– Tea olive (Osmanthus fragrantisima) or shiny-leaved holly (Ilex latifolia) are good choices for shady hedges.
“In general, these plants don’t suffer as much from the problems that plague the Leyland cypress,” Daly said. “But they still need to be given culturally appropriate conditions, such as applying the right amount of water.”
For more lawn care and landscaping resources from UGA Extension, visit extension.uga.edu/topic-areas/lawn-garden-landscapes.