Before planting Leyland cypress trees, ask yourself how badly you need fast growth. They will give you that fast growth, but you will pay for it in terms of maintenance. Learn all about these trees, including what they look like, how they are used, and how to care for them.
Plant Type, Taxonomy, and Name Origin for Leyland Cypress Trees
Plant taxonomy classifies Leyland cypress trees as x Cupressocyparis leylandii.
Different cultivars exist, having different leaf colors and measurements, including:
- Leighton Green: dark-green foliage; 40 feet tall x 8 feet wide
- Naylor's Blue: blue-gray foliage; 60 feet in height, with a spread of 10 to 15 feet
- Castlewellan: leaves tipped with gold; some bronze coloration enters in winter; staying fairly compact for years (25 to 40 feet in height), it will eventually mature to 60 to 80 feet tall, with a spread of 8 to 10 feet
- Haggerston Gray: sage-green leaves; 60 to 80 feet tall, with a width of 10 to 15 feet
- Silver Dust: blue-green foliage; height of 50 to 60 feet, with a spread of 10 to 12 feet
- Emerald Isle: bright-green leaves; 20 to 25 feet in height, with a width of 6 to 8 feet
A hybrid cross between Alaskan cedar and Monterey cypress, the Leyland cypress is classified as an evergreen tree and as a conifer. The plant is named after the man who introduced it to the world, Christopher Leyland.
Slender and fast-growing, Leyland cypress trees are generally grown by homeowners who have an urgent need for a mass of evergreen foliage to create a privacy hedge. A needled evergreen, its leaves consist of flattened sprays.
Height can vary greatly (without trimming), depending on the trees you buy and the conditions in which you grow them.
Fifty feet may be an average height for untrimmed Leyland cypresses, but do not be surprised if yours grows much higher or much shorter than that. Taller than they are wide, the spread of this columnar tree is commonly only 1/3 or 1/4 of the height (sometimes less).
Planting Zones, Sun and Soil Needs
Leyland cypress trees are best grown in planting zones 6 to 10. However, zone-5 gardeners have been successful growing them by providing their specimens during the winter with mulch and an A-frame shelter, to protect them from snow and ice damage. Such sheltering is feasible only while the plants are young (unless you keep them short by pruning). Luckily, once the plants have matured, sheltering becomes unnecessary, as they will prove to be sufficiently cold-hardy in zone 5. Nonetheless, a safer bet in zone 5 and lower is arborvitae, which has similar foliage.
Practical Landscape Uses and Ornamental Value
Since they are amenable to shearing or pruning, some homeowners take this a step further and turn such a border planting into a formal hedge. It is advisable for most folks to prune them early and often; otherwise, due to their fast growth rate, they tend to get too tall too quickly and overwhelm a landscape.
In addition to these practical landscaping uses, these plants are also used as Christmas trees.
Care: Problems, Solutions, Pruning Tips
A couple of problems with Leyland cypress trees are:
- They are shallow-rooted, meaning they can topple over easily.
- They are susceptible to canker.
To deal with canker, one Forestry expert recommends, "You should always destroy diseased plant parts and try to avoid physical damage to plants. Sanitize pruning tools between each cut by dipping in rubbing alcohol or in a solution of chlorine bleach and water."
You may also experience infestations of spider mites on this tree. A natural solution for this problem is to spray with neem oil. Another pest that can attack the plant is bagworm, the best way to deal with which is to pick the "bags" off as soon as you see them.
Their height can be controlled (you can grow them as multi-stemmed shrubs), but only through persistent pruning that starts when the plants are young. Trim the sides of Leyland cypress trees every year in July. After the leader has reached the height you want the tree to retain, make a pruning cut a few inches below that (which will leave room for the vertical growth of minor branches) to preclude any further significant upward growth, as you would do when pollarding a tree.