Tree · Cupressaceae
Leyland Cypress
Cupressus × leylandii
Hand it room to breathe and steady water, and this fast evergreen rockets up a private 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 to grab when a green wall needs to go up fast. It is a fast-growing evergreen, a happy accident that crossed Monterey cypress with Nootka cypress, and it can gain several feet a year as it fills into a dense, feathery column. That speed is the thrill of growing it, and it is also where nearly all of its challenges begin.
Here is the trade: this is a short-lived, disease-prone tree, and the usual planting habit only piles on the trouble. Wedge it into a tight single-species row and the trees crowd, the air stalls, and canker and root rot pounce. Hand each one real space, though, and it powers along for years past a crammed, neglected screen.
Grow it as a true landscape tree instead of a quick fix and it pays you back in spades. It laughs off a wide range of soils, takes shearing into a crisp formal shape, and coasts on little care once it roots in. Spacing, drainage, and steady water in dry spells are the levers that push a screen from thriving to thinning, and every one is yours to pull.
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 fight the urge to jam the trees together.
Light
Leyland cypress thrives in full sun, which packs the canopy dense and even all the way around. It will get by in partial sun or light shade, but a shaded side thins and browns sooner, and that is the exact spot where needle blight jumps in.
Water
Once it roots in it laughs off drought, yet drought stress is the very thing that unleashes deadly canker, so never let it bake bone dry. Through dry spells, soak it deeply every 7 to 14 days, and pour extra attention on young trees and any plant that is crowded or already flagging.
Soil
This tree charges into loam, clay, or sand and a wide pH of 5.0 to 8.0 without blinking. The one thing it will not stand for is poor drainage, since soggy ground fires up root rot, so break up heavy clay before you plant.
Temperature
It shrugs off both cold and heat, powering through from about -9°F to 100°F (-23°C to 38°C). That range covers a ton of climates, though ice and freeze injury can crack the bark and swing the door open for canker.
Humidity
Everyday outdoor humidity suits it, so there is no level to chase. What counts far more is air ripping through the canopy, because still, damp air around crowded plants is what stokes the foliar diseases.
Feeding
Feed it lightly in spring if at all, using a balanced complete fertilizer. Established trees hardly ever ask for any, and forcing soft, fast growth with extra nitrogen does the tree no favors.
Pruning
Prune only in dry weather, since wet cuts fling disease around, and the tree takes shearing like a champ for a formal screen. When you cut out cankered or diseased branches, drive several inches below the damage and swipe your tools with 10 percent bleach or alcohol between cuts.
Repotting
This is a landscape tree, not a container plant, so it barely ever gets potted up. If you are nursing a young one in a pot, shift it on before the roots start circling and growth stalls, then plant it out where it can run.
Size & spacing
Turned loose, it shoots to a towering 40 to 70 feet (12 to 21 m) tall and spreads 10 to 20 feet (3 to 6 m) wide. Those numbers are exactly why spacing carries so much weight, so hand each tree real distance from the next, letting air rip through and shutting disease down.
When to plant
No season traps you here, since you set out a nursery tree rather than sow it. Plant in spring or fall while the soil works easily and the weather stays mild, then let the roots dig in before the next run of heat or hard cold hits.
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
Track nearly every Leyland cypress problem back to one culprit: trees crammed too close in the wrong spot. Zero in on the lower and inner branches, where canker, blight, and root rot break out first. Match what you spot below, then pounce early, because the serious diseases shrug off any cure once they spread.
A whole branch flaring rust-brown over sunken, weeping bark
A branch flaring rust-brown above sunken, weeping bark flags Seiridium or Botryosphaeria canker, the disease that fells more Leyland cypress than any other. The fungi push in through bark wounds and race ahead on trees worn down by drought or crowding. No spray beats it, so get ahead of it: prune well below every canker, disinfect your tools between cuts, and keep the tree watered and roomy.
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
A stunted, off-color tree bogging down in soggy ground
Foliage sliding to yellow, purple, or tan while the tree thins and the roots break down calls out Phytophthora root rot, a menace of wet, packed soil. Young trees take the hardest hit. Rotted roots never bounce back, so pull the tree, destroy it, fix that drainage, and plant the next Leyland cypress somewhere fresh instead of the same hole.
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
Browning that fires up deep inside the canopy and pushes outward
When browning fires up low and deep inside the plant and spares only the tips, chase down Passalora needle blight. The fungus hitches a ride on splashing rain and camps out wherever the foliage stays wet, so it storms through crowded, shaded plants first. Open the planting up for airflow, water at the roots instead of overhead, and clip out the worst 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
Small spindle-shaped bags swinging from thinning branches
Those 1 to 2 inch (2.5 to 5 cm) silk bags studded with bits of foliage house bagworms, and the caterpillars inside will chew a branch bare. Beat them by plucking every bag through winter and early spring, before the eggs hatch. Nab the larvae while they are small and a shot of Bt wipes them out.
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 peppered yellow and bronzing under fine webbing
Fine yellow speckling that slides toward bronze, often with a bit of webbing, hands you spruce spider mites. They work the cool of spring and fall and back off in summer heat. Knock them loose with a hard blast of water, follow up with insecticidal soap or horticultural oil, and skip the broad insecticides that take out the predators doing the mites in for you.
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
Great news for pet lovers and parents: Leyland cypress is not toxic. No part of the tree poisons cats, dogs, horses, or people, so it drops right into a yard buzzing with animals and children. The one real catch lands on your hands, since the foliage can irritate skin, so pull on gloves before you prune.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
Let the cat prowl, since Leyland cypress is not toxic to cats and a curious nibble of foliage will not poison one. Gulp down a big mouthful of any plant, though, and a cat may cough it back up or feel briefly queasy, which goes for just about anything green.
Dogs Safe
Dogs romp around this tree without worry, because it packs no known toxin. Just keep an eye on the dog that chews and swallows heaps of woody foliage, which can stir up mild, passing tummy trouble.
Horses Safe
Horses graze right up to a Leyland cypress with nothing to fear. Unlike some of the truly poisonous evergreens, this hybrid holds no toxin that harms them.
Rabbits Safe
Rabbits stay safe around the foliage, and a stray bite does zero harm. It is not on their menu anyway, so they mostly breeze right past it.
Livestock Safe
Cattle, goats, and sheep share a pasture edge with this tree, which packs no poison for them. Grazing animals shrug off the resinous foliage and dive into the grass instead.
Birds Safe
Birds nest and roost in the dense canopy with no danger at all. Nothing in the foliage or the bark they peck can hurt them.
People Safe
No part of the tree poisons people, so plant it and it stays safe to grow around children. The one catch lands on the skin, not the stomach: handling the foliage can spark contact dermatitis in some people, so pull on gloves before 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, split apart mainly by color and habit. Here are the ones you will most likely spot at the nursery.
Leighton Green
The go-to classic, a tall, dense, columnar tree in deep green that southern growers grab to raise a fast screen or a homegrown Christmas tree.
Castlewellan
A more compact pick whose gold-tipped foliage fires up its brightest yellow through fall, winter, and spring.
Naylor's Blue
A looser, more openly branched column flaunting blue-gray foliage on a frame that climbs a touch slower.
Murray
A vigorous dark green type grown much like the classic to throw up a quick privacy wall.
How to propagate
Because it is a sterile hybrid, you cannot raise this tree true from seed, so every new plant launches as a copy taken off an existing one.
Stem cuttingsModerate
Late summer to fall (semi-hardwood cuttings) · Several weeks to months to root
This sterile hybrid will not come true from seed, so cuttings carry the day. Snip semi-hardwood cuttings from late summer into fall, then hold your nerve, because they can take several weeks to a few months to fire out roots.
GraftingDemanding
Dormant season · Weeks to months
Keen growers graft it in the dormant season, coaxing the union together over weeks to months. It takes real skill, though, and shows up far less often than rooted cuttings for landscape stock.
Myths
Leyland cypress is a maintenance-free, plant-it-and-forget-it instant hedge.
It rockets up, sure, but it lives short and catches disease easily, and it takes the worst beating jammed tight as a single-species wall. Crowding and drought stress throw the gate open to Seiridium and Botryosphaeria cankers, needle blight, and root rot, while the shallow roots leave a big tree ready to go over in a storm. Hand it real room and steady water, and it rewards you as a lively screen instead of a headache.
Cankers and needle blight can be sprayed away with fungicide.
Once a canker digs in, no spray cures it, so drop that plan. The moves that actually work are all cultural: cut out the diseased wood, take the load off the tree, space the planting right, and keep your tools clean.