My lettuce has white spots: What to do about white spots on lettuce

Then suddenly you’re a healthy green salad with white spots. You thought you’d done everything you could to keep your plants healthy, so why do your lettuces have white spots? A lettuce with white spots can mean different things, usually a fungal disease, but not always. Read on to find out what causes white spots on lettuce plants.

Why does my lettuce have white spots?

First of all, take a good look at the white spots. Actually, it’s better than looking, to see if you can clean the stains. Yes ? If so, it’s likely that something in the air fell on the leaves. It could be ash from a nearby forest fire or dust from a nearby quarry.
If you can’t remove the white spots from the lettuce, it’s probably due to a fungal disease. Some diseases are milder than others, but even so, fungi spread by spores that are quite difficult to control. Since the tender leaf of lettuce is eaten, I do not recommend spraying lettuce with white spots that are suspected to be caused by a fungus.

Mushroom reasons for lettuce with white spots

Late blight is my main culprit, simply because it seems to attack all kinds of vegetation. Pale yellow to very light green spots appear on the ripe leaves of lettuce. As the disease progresses, the leaves become white and mouldy and the plant dies.
Powdery mildew develops on infected crop residues. The spores are carried by wind. Symptoms appear within 5 to 10 days after infection, often after cool, wet weather with heavy rain, fog or dew. If mildew is suspected, the best solution is to remove and destroy the plant. Next time, plant lettuce varieties resistant to this disease such as Arctic King, Big Boston, Salad Bowl and Imperial. Also, keep the garden free of plant debris that harbours fungi.
Another possibility is called white rust or Albugo candida . Another fungal disease, white rust can generally affect not only lettuce but also mizuna, Chinese cabbage, radish and mustard greens. The first symptoms are white spots or pustules on the underside of the leaves. As the disease progresses, the leaves turn brown and wilt.
As with late blight, remove infected plants. In the future, plant-resistant varieties will use drip irrigation or focus on watering the base of the plant to keep the leaves dry, as fungal infections usually coincide with persistent leaf wetness.