Why Is My Italian Cypress Turning Brown? 5 Causes and the Fix for Each

An Italian cypress that starts going brown is the landscape equivalent of a slow alarm. The tree is the signature exclamation mark of the Mediterranean villa — Roman, Tuscan, Levantine, Istanbulite — and when its dark green sleeve of foliage begins to fade, it reads across the entire garden. By the time brown is obvious from forty metres away, the problem has usually been moving for weeks.

Here is the honest answer: there are five different reasons an Italian cypress turns brown, and the right fix depends entirely on which one you are dealing with. Most home treatments make the tree worse because the diagnosis is wrong — generic "tree food" poured around a cypress with root rot is a death sentence.

This is the diagnostic order we use inside the NAS atelier when a client calls about a browning cypress. Work through it in sequence.

1. Seiridium canker — the single most common killer

Across Türkiye, the Levant, and the wider Mediterranean, this fungal canker is the number-one cause of Italian cypress decline. It enters through any wound — a pruning cut, a frost crack, a mower strike — and eats the tree from the inside.

What it looks like: Individual branches turn yellow then rust-brown while the rest of the tree is still green. Look closely at the dying branch and you will find a sunken, darkened lesion on the bark near the main stem, often weeping a dried amber resin. The browning does not cross from one branch to another through the air — it moves inside the wood.

The test: Peel a small sliver of bark below the sunken lesion with a clean knife. Healthy inner bark is bright green. Infected inner bark is brown or rust-coloured.

The fix: Prune out every infected branch at least 20 cm below the last visible canker, sterilising your blade with 70% isopropyl alcohol between every single cut. Burn or bag the prunings — never compost them. There is no effective spray for an active canker; prevention matters more than cure. Seal large pruning wounds with a proper tree wound dressing, never with roof paint or bitumen.

2. Phytophthora root rot — from the ground up

Italian cypress is a drought-adapted tree. Its roots evolved on dry, rocky Mediterranean slopes. Plant one in heavy clay, or sink one into an irrigation zone designed for a lawn, and the root system suffocates.

What it looks like: Uniform browning that starts at the base of the tree and works upward. The soil around the trunk stays wet more than 48 hours after watering. Often the trunk shows a darker discoloration at the soil line.

The test: Push a long screwdriver into the soil 30 cm from the trunk. If it slides in easily for the full length and the withdrawn tip is wet, the root zone is waterlogged.

The fix: Stop all irrigation within a three-metre radius of the trunk for three to four weeks. If the cypress shares a zone with a lawn or irrigation bed, redesign the irrigation — cypresses need their own low-frequency drip line or, better, no supplemental water at all once established. In severe cases with mature specimens, our atelier excavates the root crown, builds a gravel-lined dry well around it, and re-grades to drain away from the tree.

3. Drought stress — the opposite problem

A young or newly planted cypress has not yet sent roots deep enough to find moisture in a Mediterranean summer. If it dries out past a threshold, the foliage browns uniformly — and unlike root rot, the damage is crisp, not soft.

What it looks like: Rapid, uniform browning across the whole tree in a single heat spell, with the foliage feeling dry and brittle to the touch. The topsoil is bone dry 10 cm down. Usually only affects trees under three years in the ground.

The fix: Deep soak — 80 to 120 litres, delivered slowly over an hour at the drip line — and repeat weekly through the first two summers. After that, the tree should be self-sufficient. Do not shower the foliage; water the root zone.

4. Cypress aphid or spider mite — the silent drinkers

These pests are small enough to miss and devastating enough to kill a decade-old specimen in a single season. The cypress aphid (Cinara cupressi) feeds on sap from inside the foliage; spider mites do the same on the outside.

What it looks like: A greyish-green desaturation of the foliage that matures into patchy brown, starting in the interior of the tree rather than the tips. Fine webbing visible on the twigs in the case of mites. Small clusters of aphid-sized grey insects under the foliage in the case of cypress aphid. Often the browning is concentrated on the sun-exposed southern face of the tree.

The test: Tap an affected branch sharply over a sheet of white paper. If specks move on the paper, you have mites. A 10x hand lens confirms the species.

The fix: Two thorough applications of horticultural oil (neem oil or plant-derived soybean oil work), ten days apart, drenching the foliage from the inside out. For heavy cypress aphid infestations, a systemic treatment applied by a licensed arborist. Do not use broad-spectrum insecticide on a cypress unless you want to trigger a spider-mite explosion by killing the predators.

5. Winter burn and salt damage

In Istanbul and the higher-elevation Levant, a hard winter wind on a sunny cold day desiccates the foliage faster than the frozen root system can replace moisture. On coastal Gulf and Mediterranean sites, salt spray has the same effect.

What it looks like: Browning concentrated on one side — the windward face, or the side facing the sea. The rest of the tree is green. The pattern appears suddenly in January or February.

The fix: Nothing in the short term. Do not prune the brown foliage until May, because it still offers thermal protection to the live tissue behind it. In May, selectively prune out the dead, and in autumn apply an anti-desiccant spray to the foliage before the first hard frost. For new plantings in exposed positions, a temporary burlap screen through the first winter prevents the problem entirely.

When to call us

A cypress is a forty-to-hundred-year commitment. Call the atelier — us, or another trusted firm — when:

• More than a third of the tree is brown and you are not sure which of the five causes is at play
• Lesions with resin are visible on the main trunk, not just side branches
• The browning has crossed from one tree to the next in a hedge — a sign Seiridium is moving
• The specimen is mature (twenty years and older) and you want an independent diagnosis before treatment

An Italian cypress carries a villa garden. Losing one is not a minor event. Send a photo to WhatsApp +90 535 422 5227 — a real landscape architect will look at it the same working day. No charge for the first read.

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NAS Landscape has planted, pruned, and diagnosed Italian cypresses across Türkiye, the Levant, and the Gulf since 1965. Written by MHD ZUHIR MADAMANI, Istanbul.