What diseases affect basil?

Downy Mildew, Fusarium wilt, Grey mould, Tomato spotted wilt virus

Basil pests and diseases: how to recognise them

Q: Which basil problems need quick action?

Downy Mildew: Badly affected leaves shrivel and turn brown or yellow and fall early; plants become stunted and some may die. Fusarium wilt: Wilting and yellowing that often starts on one side of the plant, a branch or even a leaf; lower leaves yellow first. Grey mould: Fuzzy grey-brown mould on decaying buds, flowers, leaves, stems or fruit in humid weather. Tomato spotted wilt virus: Young leaves with a bronze cast that later show small dark brown spots; leaves may cup or roll.

Ocimum basilicum

The pests, diseases and disorders recorded for basil in our library, each with a photo and its first symptom. Every page has the full list of symptoms, organic and chemical treatment and prevention.

At a glance

Problems in total	6
Pests	2
Diseases	4
Need quick action	4

How to grow basil · All pests and diseases

Pests

Leaf MinerHeavily mined leaves dry up or drop early; badly affected tomato plants can lose most of their leaves.Photo: Flowersabc, CC BY-SA 2.0, Wikimedia Commons
WhiteflyClouds of tiny white-winged insects, about 1.5 mm long, fly up when the plant is disturbed.Photo: gaucho, CC BY-SA 3.0, Wikimedia Commons

Diseases

Which basil problems need quick action?

These spread or do lasting harm fast; check the plants and start treatment the day you see them.

Downy Mildew: Pale green, yellow, purple or brown blotches on the upper side of leaves, often angular where they are bordered by the veins.
Fusarium wilt: At first the plant seems to recover overnight, but the wilt soon becomes permanent; growth is stunted and few fruits form.
Grey mould: Small, almost translucent spots that turn brown and water-soaked; affected tissue goes soft, dark and dies, and buds and flowers shrivel.
Tomato spotted wilt virus: Dark brown streaks on stems and leaf stalks; tips die back, and plants are stunted or grow lopsided.

Plants with many of the same problems

Which plants each problem affects: sources

The links between these problems and the plant were checked against these pages.