All grapevine problems

Fungal moderate

Anthracnose

Sunken spots with dark margins on shoots and berries — the classic "bird's-eye rot".

Fungal high

Armillaria root rot

A soilborne fungus that rots roots and crown, killing vines in a slowly widening patch.

Fungal moderate

Bitter rot

A late-season berry rot that softens ripe fruit and leaves it bitter — often riding in behind other rots.

Fungal high

Black foot & Petri disease

Soilborne trunk-disease fungi that rot the base and wood of young vines, causing them to fail in the first years.

Fungal high

Black rot

Tan leaf spots ringed with black dots, and berries that shrivel into hard black mummies.

Disorder moderate

Boron deficiency

Poor fruit set with "hen and chicks" clusters and dying shoot tips — common on dry, sandy soils.

Fungal high

Botryosphaeria dieback

A trunk-disease complex that cankers cordons and kills spurs, closely mimicking Eutypa.

Fungal moderate

Botrytis bunch rot (grey mould)

Fuzzy grey mould that rots ripening clusters, especially after rain near harvest.

Bacterial moderate

Crown gall

Warty, tumour-like growths on the trunk near the soil line, often after winter injury.

Fungal high

Downy mildew

Yellow "oil spots" on top of the leaf with white fuzz underneath — loves wet, warm weather.

Fungal high

Esca (trunk disease)

A chronic wood rot of older vines, showing as "tiger-stripe" leaves and sudden collapse.

Insect / pest moderate

European grapevine moth

The main cluster caterpillar of European vineyards — eats flowers, then berries, inviting rot.

Fungal high

Eutypa dieback

A slow trunk disease ("dead arm") that stunts spring shoots and kills cordons one arm at a time.

Insect / pest high

Grape berry moth

Caterpillars that web and bore into berries, opening the door to bunch rots.

Insect / pest low

Grape erineum mite

A microscopic blister mite that raises fuzzy welts on leaves — alarming but rarely harmful.

Insect / pest moderate

Grape leafhopper

Small hoppers whose feeding stipples leaves white; heavy numbers scorch the canopy.

Insect / pest moderate

Grape mealybug

Soft, waxy sap-suckers that foul clusters with honeydew — and spread leafroll virus.

Insect / pest high

Grape phylloxera

A tiny root-feeding aphid-like insect that devastates own-rooted European grapes.

Fungal moderate

Grape rust

Bright orange pustules that dust the underside of leaves, causing early leaf drop in warm regions.

Viral high

Grapevine fanleaf virus

A nematode-spread virus that deforms leaves into a fan shape and leaves the crop straggly.

Viral moderate

Grapevine leafroll

Autumn leaves that roll downward and turn deep red or yellow while the veins stay green.

Viral moderate

Grapevine red blotch

Red blotches on leaves that mimic leafroll but mainly delay ripening and lower sugar.

Disorder moderate

Herbicide drift

Distorted, cupped, fan-shaped new growth from weed-killer that drifted onto the vine — not a disease at all.

Disorder moderate

Iron deficiency

Yellowing of the youngest tip leaves with green veins — usually a high-pH soil problem, not a lack of iron.

Insect / pest moderate

Japanese beetle

Metallic beetles that skeletonise leaves, chewing the tissue between the veins into lace.

Disorder low

Magnesium deficiency

Yellowing between the veins of older leaves while the veins stay green — one of the commonest grape disorders.

Disorder low

Nitrogen deficiency

Uniformly pale, small leaves and weak growth from too little nitrogen — the vine simply lacks vigour.

Fungal moderate

Phomopsis cane & leaf spot

Black specks and cracked bark on the base of shoots, plus small spots on lower leaves.

Bacterial high

Pierce's disease

A bacterium spread by sharpshooter insects that clogs the vine's plumbing and kills it over 1–3 years.

Disorder moderate

Potassium deficiency

Scorched, curling leaf margins on older leaves and poorly ripening fruit — a heavy-cropping vine's shortfall.

Fungal high

Powdery mildew

A dusty white-grey coating on leaves and berries — the most common grape fungus almost everywhere.

Fungal moderate

Ripe rot

Reddish-brown circular rot on ripening berries, often oozing salmon-pink spores.

Insect / pest moderate

Root-knot nematode

Microscopic soil roundworms that gall the roots and stunt vines, especially on sandy soils.

Fungal moderate

Sour rot

Clusters that turn to vinegar-smelling mush late in the season, swarming with fruit flies.

Insect / pest moderate

Spider mites

Tiny sap-sucking mites that stipple and bronze leaves in hot, dusty, dry conditions.

Insect / pest high

Spotted lanternfly

An invasive planthopper that swarms vines, sucking sap and coating them in sticky honeydew and sooty mould.

Disorder moderate

Sunburn & sunscald

Heat and intense sun scorching exposed berries and leaves — often triggered by over-thinning the canopy.

Disorder high

Winter & frost injury

Cold damage that kills buds, splits bark, and kills trunks — a frequent look-alike for trunk disease.

Disorder moderate

Zinc deficiency

Small "little leaf" growth and straggly, shot-berry clusters — a look-alike for fanleaf virus.