Fungal
Alternaria Blight
A fungal disease causing dark bullseye-patterned spots on leaves and stems, often triggering early defoliation and reducing yield in warm, wet conditions.
Symptoms to Look For
- Dark brown circular spots with concentric ring patterns on older leaves
- Yellow halos surrounding spots, causing premature leaf yellowing and drop
- Dark sunken lesions on fruit and stem collars in severe cases
Affected Plants
TomatoPotatoCarrotBrassicaPepperBeetrootOnion
Organic Solutions
Copper spray
Apply copper-based fungicide spray preventatively from transplanting, repeating every 7 - 14 days during warm wet weather.
Remove infected leaves
Strip and destroy spotted leaves as soon as they appear to reduce spore load and slow the spread up the plant.
Organic Remedies
Prevention
- Rotate crops for at least 3 years to prevent spore build-up in the soil
- Avoid overhead irrigation and water at the base of plants in the morning
- Choose resistant varieties where catalogue listings indicate Alternaria resistance
Garden, by Willowbottom recommends only organic, wildlife-friendly solutions. No synthetic pesticides, no harmful chemicals - ever.