Tree · Cupressaceae
Leyland Cypress
Cupressus × leylandii
Given room to breathe and steady water, this fast evergreen raises a dense, feathery green wall in just a few years.
Full sun
Every 7–14 days
USDA 6–10
40–70 ft · 12.2–21.3 m
Overview
Leyland cypress is the tree people reach for when they want a green wall and want it soon. It is a fast-growing evergreen, an accidental cross between Monterey cypress and Nootka cypress, and it climbs several feet a year into a dense, feathery column of flattened green sprays. That speed is the whole appeal, and it is also the root of most of its trouble.
Up close, the foliage grows in soft, scale-covered fans that press together into a solid wall of green, so dense that light barely reaches the twigs deep inside. That thick interior is part of the catch, because this is a short-lived, disease-prone tree: crowd the plants and the airless heart of the canopy is where cankers stain the bark and browning creeps through the shaded needles. Give each tree real space and that dense green stays sound far longer.
The color and texture shift by selection, from the deep, dark green of the standard forms to gold-tipped and soft blue-gray foliage, all carried on that same feathery, columnar frame. It takes a range of soils, holds a crisp edge under shearing, and asks little once its roots settle. Spacing, drainage, and steady water in dry spells are what keep the needles green and full rather than thin and rust-brown.
Care
The short version: full sun, well-drained soil, and plenty of room between plants. Water deeply in dry spells, prune only when the weather is dry, and give each feathery column the space it needs.
Light
Leyland cypress grows best in full sun, which keeps the feathery canopy dense and evenly green all the way around. It will take partial sun or light shade, but a shaded side thins and browns sooner, and that shaded, sunless flank is exactly where needle blight likes to start.
Water
Once established it handles drought, yet drought stress is what triggers deadly canker, so the tree should not run bone dry. During dry spells, water deeply every 7 to 14 days, giving extra attention to young trees and to any plant that is crowded or already thinning and browning.
Soil
This tree adapts to loam, clay, or sand across a wide pH of 5.0 to 8.0. The one thing it will not forgive is poor drainage, since soggy ground rots the roots and drains the foliage to sickly yellow and tan, so amend heavy clay before you plant.
Temperature
It is cold-hardy and heat-tolerant, holding up from about -9°F to 100°F (-23°C to 38°C). That range covers many climates, though ice and freeze injury can split the bark and open the door to canker.
Humidity
Ordinary outdoor humidity suits it, so there is no level to manage. What matters far more is air moving through the canopy, because still, damp air trapped in the dense foliage of crowded plants is what fuels the browning foliar diseases.
Feeding
Feed lightly in spring if at all, using a balanced complete fertilizer. Established trees rarely need any, and pushing soft, fast growth with extra nitrogen does the tree no favors.
Pruning
Prune only in dry weather, since wet cuts spread disease, and the tree takes shearing well into a crisp, formal green face. When you cut out cankered or diseased branches, go several inches below the sunken, stained damage and wipe your tools with 10 percent bleach or alcohol between cuts.
Repotting
This is a landscape tree, not a container plant, so it is rarely potted up. If you are holding a young one in a nursery pot, move it on before the roots start circling and growth stalls, then set it into the ground.
Size & spacing
Left to grow, it rises to a towering 40 to 70 feet (12 to 21 m) tall and spreads its feathery limbs 10 to 20 feet (3 to 6 m) wide. Those figures are the reason spacing matters so much: give each tree real distance from the next so air can move through the dense foliage and disease stays down.
When to plant
Season is not a worry, since you set out a nursery tree rather than sow it. Plant in spring or fall while the soil is workable and the weather is mild, and let the roots take hold before the next stretch of heat or hard cold.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: spring or fall
Hardiness
USDA hardiness zones: 6–10
Temperature: down to -23°C
Troubleshooting
Almost every Leyland cypress problem traces back to one thing: trees planted too close in the wrong spot. Look into the lower and inner branches, deep in the shaded heart of the canopy, where canker stains the bark and browning shows first. Match what you see below, then act early, because the serious diseases have no cure once they spread.
A branch fading through yellow to rust-brown above sunken, resin-beaded bark
A branch that pales to yellow and then to a dry rust-brown, set above sunken bark stained dark brown to purple and beaded with resin, shows Seiridium or Botryosphaeria canker. This is the disease that kills more Leyland cypress than anything else. The fungi enter through breaks in the bark and take hold fastest on trees worn thin by drought or crowding. No spray cures it, so cut well below each sunken lesion, disinfect the blades between cuts, and keep the tree watered and spaced.
Fix:
- Prune out infected branches several inches below the canker and destroy them
- Disinfect pruning tools with 10 percent bleach or alcohol between every cut
- Reduce stress by deep watering during drought and mulching beyond the lowest limbs
- Remove severely declined trees as there is no chemical cure
Thin, off-color foliage in yellow, purple, and tan above rotting roots
Foliage that thins and drains to sickly yellow, purple, and tan while the tips die back and the roots below turn dark and soft points to Phytophthora root rot. It sets in on wet, compacted ground and strikes young plants hardest. Once the roots decay there is no bringing the tree back, so dig it out, destroy it, correct the drainage, and set the next Leyland cypress in fresh ground.
Fix:
- Remove and destroy infected plants and do not replant Leyland cypress in the same spot
- Improve drainage and amend heavy clay with organic matter
- Avoid overwatering and waterlogged sites
Brown creeping through the inner needles while the tips stay green
When the needles brown deep in the shaded interior and low on the plant while only the outer tips keep their green, the cause is usually Passalora needle blight. The fungus rides on splashing rain and settles wherever the flattened sprays of foliage stay wet, so crowded, shaded plants brown first. Open the planting for airflow, water at the roots rather than over the leaves, and cut out the worst-browned branches.
Fix:
- Space and thin plantings to improve airflow and reduce leaf wetness
- Switch to drip irrigation or water early in the morning, avoiding overhead watering
- Prune out and destroy diseased branches
- Apply a labeled fungicide (e.g., thiophanate-methyl or myclobutanil) preventively from late spring through summer if needed
Spindle-shaped silk bags dressed in foliage dangling from bare branches
The 1 to 2 inch (2.5 to 5 cm) spindle-shaped silk bags, shingled all over with snipped bits of the tree's own foliage, are the cases of bagworms. The caterpillars hidden inside chew branches down to bare twigs. Pull the bags off by hand through winter and early spring, before the eggs hatch. While the larvae are still small, a spray of Bt clears them.
Fix:
- Hand-pick and destroy bags in winter and early spring
- Apply Bacillus thuringiensis (Bt) when larvae are small in spring
- Use a labeled contact insecticide for heavy mature infestations
Needles pinpricked yellow and dulling to bronze beneath fine webbing
A fine yellow stipple pricked across the needles, dulling over time to a flat bronze and veiled here and there in fine webbing, is the feeding of spruce spider mites. These tiny creatures work the cool of spring and fall rather than the summer heat. Knock them off with a hard jet of water, then treat with insecticidal soap or horticultural oil, and leave the broad insecticides alone, since they kill the predators that hold the mites down.
Fix:
- Spray plants forcefully with water to dislodge mites
- Apply insecticidal soap, horticultural oil, or neem oil
- Avoid broad-spectrum insecticides that kill predatory mites
Toxicity
Good news for pet owners and parents: Leyland cypress is not toxic. No part of the tree, needle or wood, poisons cats, dogs, horses, or people, so it is a safe choice for a yard with animals and children. The one real caution is for your skin, since brushing the foliage can irritate it, so wear gloves when you prune.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
Leyland cypress is not toxic to cats, and a curious nibble at the soft green sprays will not poison one. A cat that swallows a large amount of any plant may bring it back up or have a brief upset stomach, which holds true for almost anything green.
Dogs Safe
The foliage holds no known toxin, so dogs are safe around the tree. The only thing to watch is a dog that chews and swallows a lot of the woody, resinous foliage, which can bring on mild, passing tummy trouble.
Horses Safe
Horses grazing beside a Leyland cypress have nothing to fear. Unlike some genuinely poisonous evergreens, this hybrid carries no toxin in its needles or wood that would harm them.
Rabbits Safe
Rabbits are safe around the foliage, and a stray bite at the scaly green sprays does no harm. It is not a food plant for them, so they rarely nibble it at all.
Livestock Safe
Cattle, goats, and sheep can share a pasture edge with this tree, which holds no poison for them. Grazing animals tend to leave the resinous foliage alone and crop the grass instead.
Birds Safe
Birds nest and shelter in the dense, feathery canopy with no danger at all. Nothing in the needles or the bark they peck carries any harm.
People Safe
No part of the tree poisons people, so it is safe to grow around children. The one catch is the skin rather than the stomach: brushing and handling the foliage can bring on contact dermatitis in some people, so wear gloves when you prune.
Wear gloves when pruning or handling foliage to avoid skin irritation.
Varieties
Most Leyland cypress sold for screens is one of a few named selections, told apart mainly by the color of the foliage and the tightness of the column. These are the ones you are likely to meet at the nursery.
Leighton Green
The long-standing standard, a tall, dense, columnar tree whose flattened sprays of dark green foliage make it a favorite of southern growers for a fast screen or a homegrown Christmas tree.
Castlewellan
A more compact selection tipped in gold, its new growth flushing its brightest, warmest yellow through fall, winter, and spring.
Naylor's Blue
A looser, more openly branched column clothed in soft blue-gray foliage on a slightly slower-growing frame.
Murray
A vigorous form of deep, dark green grown much like the standard for putting up a quick privacy wall.
How to propagate
Because it is a sterile hybrid, you cannot grow this tree true from seed, so every new plant is a copy taken from an existing one.
Stem cuttingsModerate
Late summer to fall (semi-hardwood cuttings) · Several weeks to months to root
As a sterile hybrid it will not come true from seed, so cuttings are the usual route. Take firm semi-hardwood cuttings from late summer into fall, and be patient, because the cut stems can take several weeks to a few months to push out roots.
GraftingDemanding
Dormant season · Weeks to months
Some growers graft it in the dormant season, the union slowly knitting over weeks to months. It is exacting work, though, and far less common than rooted cuttings for landscape stock.
Myths
Leyland cypress is a maintenance-free, plant-it-and-forget-it instant hedge.
It grows fast into a feathery green column, but it is short-lived and prone to disease, and it suffers most when packed tight as a single-species wall. Crowding and drought stress open the way to Seiridium and Botryosphaeria cankers that sink and stain the bark, to browning needle blight, and to root rot, while the shallow roots leave a big tree ready to topple in a storm. Give it real room and steady water, or it becomes a high-maintenance screen rather than a carefree one.
Cankers and needle blight can be cured by spraying the tree with fungicide.
Once a canker sinks into the bark, no spray will cure it. The only real management is cultural: prune out the diseased wood, ease the tree's stress, space the planting properly, and keep your tools clean.