Backyard Grapes Identify & treat grapevine problems
Viral moderate severity

Grapevine leafroll

Grapevine leafroll-associated virus (GLRaV)

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

Reddened, downward-rolling leaves of a red grape variety infected with grapevine leafroll disease Plantix
Grapevine leafroll disease: red, downward-cupped leaves with veins remaining green Photo: Ed Hellman, Texas AgriLife Extension California Department of Food and Agriculture, PD/GWSS Board
Red-variety grapevines with leafroll: leaves roll downwards and turn intense red long before autumn Photo: Roderick Bonfiglioli (private collection) Te Ara – the Encyclopedia of New Zealand

Description

Grapevine leafroll is a viral disease (a complex of several related viruses) that cannot be cured — an infected vine stays infected for life. Its autumn display is striking and easy to recognise: leaves roll under and colour up brightly while the veins remain green.

The virus travels two ways: inside infected cuttings and nursery plants, and between vines on mealybugs and scale insects. For a home grower, the whole game is prevention — buy clean stock, and keep the insect vectors in check so a single infected vine doesn’t seed the rest of the row.

What to look for

  • Leaves cup and roll downward at the edges, especially later in the season.
  • Reds/purples in dark varieties, or yellowing in white varieties, between the veins.
  • The main veins stay noticeably green against the coloured leaf.
  • Delayed ripening, poor colour, and lower sugar in the fruit.

Treatment options

Cultural & prevention

Start here — habits that stop problems before they spread.

  • Start with certified virus-tested planting stock — this is the main defence.
  • Remove and replace confirmed infected vines to limit spread.
  • Control mealybugs and soft scale, which move the virus vine-to-vine.

Organic / low-toxicity

Gentler sprays and biologicals for active outbreaks.

  • Manage mealybug/scale with horticultural oil and by supporting natural predators.

Conventional fungicide / pesticide

For severe cases. Always follow the product label.

  • No cure for the virus itself; insecticides target the insect vectors only.

Sources

This entry is based on the references below. Read them for full detail and for spray timings and rates valid where you live.

  1. Grapevine Leafroll Disease — Washington State University Extension
  2. Virus Diseases - Grape Pest Management Guidelines — UC IPM
  3. Red Leaves in the Vineyard: Biotic and Abiotic Causes (FS1260) — Rutgers NJAES Cooperative Extension
  4. Ecology and Management of Grapevine Leafroll Disease — Frontiers in Microbiology (2013)