Chilli Plant Diseases

Most chilli disease trouble starts with stressed plants and wet conditions that linger too long. Auckland growers know the pattern: a wet spell, packed foliage and a pot that stays soggy can undo an otherwise healthy plant. Good airflow, clean tools, sensible spacing and free-draining mix are boring advice because they work.

When you spot a problem, slow down before treating it. Check which leaves are affected, whether it's spreading, and whether the plant is sitting wet around the roots. Remove fallen leaves and fruit, water the soil rather than the foliage, and wash your hands and tools before moving from a suspect plant to a healthy one.

Common chilli diseases

• Mosaic virus shows as mottled, puckered or distorted leaves. Affected plants are best removed.
• Bacterial leaf spot leaves dark, water-soaked spots, and spreads in splashy, wet weather.
• Bacterial rot turns stems or fruit soft and mushy. Hygiene matters most here.
• Phytophthora blight causes collapse at the base of the stem, usually in wet, poorly drained soil.
• Powdery mildew is a white, dusty coating on the leaves, worst in humid, still air.
• Verticillium wilt is wilting that doesn't recover after watering, often starting on one side of the plant.

Don't expect a single spray to fix every disease. Once a virus is established, removing the plant and stopping the spread is usually the honest answer. With bacterial problems, cut down leaf wetness, improve airflow and keep hands, pots and tools clean before working through the rest of the crop.

Start prevention at spring planting. Through Auckland's humid summers, keep foliage open and check plants after heavy rain. If you're growing under cover, ventilate early on warm days and don't leave trays or pots standing in water.