Unfortunately, like other vegetables, lettuce is afflicted with diseases from time to time. Find out below which diseases lettuce can suffer from, how to recognize them and what you can do about them.

Too much moisture makes the lettuce sick

These diseases occur in lettuce

The most common disease affecting lettuce is downy mildew. Lettuce can also contract lettuce blight and various viruses.

Wrong mildew

Downy mildew can only be treated if it is discovered in good time. If the infestation is severe, the offending lettuce should be removed immediately to prevent the disease from spreading.

Causes of downy mildew

Downy mildew occurs when the weather is constantly too damp and the leaves are lying directly on the wet ground.

Identify downy mildew

Lettuce affected by downy mildew shows yellow-brown spots on the upper leaf surface and white-grayish spores on the underside of the leaf.

Prevent and control downy mildew

  • Prevent too much moisture, raise lettuce with brushwood or similar from the ground or aerate it if it rains for a long time
  • Avoid nitrogen-containing fertilization
  • remove diseased leaves
  • Treat infested lettuce with a decoction of onions, garlic and horsetail

lettuce rot

Lettuce rot is usually a mixture of different infections and is also due to too much moisture. Symptoms are rotten spots on the underside of the leaf.
The measures are similar to those for downy mildew disease:

  • Cut off diseased leaves
  • ensure better ventilation, avoid moisture
  • Liming if the pH value is too low

prevent diseases

Most diseases are caused by excessive moisture and a weakened plant. As a preventive measure, you should therefore generally:

  • Pay attention to crop rotation (only plant lettuce in the same place every three to four years)
  • ensure adequate ventilation
  • Remove weeds regularly
  • don't water too much
  • Avoid waterlogging
  • possibly lime if the pH value is too low
  • don't plant too densely

Disease-resistant lettuce varieties

If you've struggled with lettuce diseases in the past, you'll probably be pleased to know that resistant varieties exist. The early varieties Dynamite and Merveille des 4 Saisons are particularly resistant to viruses and diseases. An overview of other early, middle and late varieties can be found here.

Category:

Vegetable garden