Gadenin日本語Get the appCheck these first
- What colour are the spots, and do they have a yellow halo?
- Are there concentric rings or a mosaic pattern?
- Are the spots only on leaves, or also on stems and fruit?
Most likely causes
From the pests and diseases recorded for this plant, the ones whose symptoms match, most serious first. Symptoms alone rarely confirm a cause, so use the linked page to check the signs and treatment.
Onion Yellow Dwarf
Yellow streaks appear along the leaves, which twist and lodge easily. The whole plant is stunted and the bulb and leaf sheaths bulk up very poorly.
How to identify and treat: Onion Yellow DwarfDowny Mildew
Pale yellow to yellow-brown angular lesions form on the upper leaf surface with a gray-purple mold in the matching spot underneath. Lesions merge, the leaves die back and the plant declines early.
How to identify and treat: Downy MildewBacterial Spot
Small water-soaked spots appear on the leaves, later turning brown with yellowing around them. Fruit develops water-soaked or scabby spots from which rot spreads.
General description; not specific to this plant.
How to identify and treat: Bacterial SpotOther possible causes
- Bacterial Canker — Leaf margins scorch and die back, and splitting the stem reveals browned vascular tissue. …
- Gray Mold — Water-soaked brown lesions form on flowers, fruit and leaves, densely covered by a fuzzy g…
- Late Blight — Dark green water-soaked lesions appear on the leaves and expand quickly into brown dead ti…
- Anthracnose — Light brown to dark brown round lesions with sharp margins form on leaves and fruit, sligh…
- Rust — Small raised orange-yellow to red-brown pustules form on both leaf surfaces, then rupture …
Other symptoms on this plant
What other growers did about it
A page like this one can tell you what onion leaf spots is and what to try. What it cannot tell you is what actually happened to someone who had it on the same plant, at the same point in the season, and what they did next.
Gadenin is a free garden journal built around that. You photograph the plant, tag what you are seeing, and the entries line up by date for each plant you grow.
- Tag the problem and the app tells you how many other growers have logged the same thing on the same plant.
- Growers who make their records public can be followed, so you can read what they did and how it turned out.
- Next season your own entries come back at the same point in the year, so you check the plant before it starts.
Free on iPhone. Recording, tagging and reading public records cost nothing.