Pepper mottled leaves

There are 3 common causes, and they need completely different responses — so working out which one you have matters more than treating quickly.

2 of them can kill the plant. Rule those out first.

Check these two things first

  • Push a finger into the soil, two knuckles deep. Wet soil plus a wilting plant means too much water, not too little — and it is the commonest reason a plant is dying. Dry soil plus crisp leaves means the opposite. The leaves look nearly identical either way, so the soil is what tells you.
  • Turn a damaged leaf over. Half of all diagnoses live on the underside: fuzz means downy mildew, fine webbing means spider mites, clusters of insects mean aphids. Nothing on the top of a leaf is as informative.

Most garden problems are cosmetic and resolve without treatment. Reach for a spray last, not first.

The 3 causes, and how to tell them apart

1.Mosaic Virus

Act now

Virus

A patchwork of light and dark green across the leaf, giving a mottled or marbled look with no clear spot edges. New leaves come out narrow, puckered, strap-like or fern-like. Fruit is small, mottled and often fails to set.

How to know it is this one

Light and dark green mottling with soft, blurred boundaries.

Full treatment for mosaic virus

2.Spider Mites

Act now

Pest

Fine pale stippling across the leaf, as though it had been sprayed with a very fine dust of pinpricks. Leaves go bronze or grey, and fine webbing appears between leaves and along stems in bad infestations. The mites themselves are just visible as moving specks.

How to know it is this one

Fine even stippling rather than discrete spots or holes.

Full treatment for spider mites

3.Thrips

Treatable

Pest

Silvery or bronze streaking on leaves and petals, speckled with minute black dots of excrement. Flowers open distorted or streaked. The insects themselves are slender slivers under a millimetre long that dart when disturbed.

How to know it is this one

Silvery or bronze streaks, not spots or holes.

Full treatment for thrips

Still not sure?

The diagnostic key adds two more questions — which part is affected and where the trouble started — and those usually settle it.

Run the diagnostic key