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Bay laurel spots on leaves: causes and what to do

8 results in the diagnosis tree begin with spots on the leaves, 5 of them marked likely when the answers fit. They are ordered here for Bay laurel (Laurus nobilis), using what its sources say about light, soil moisture, humidity and pests and diseases and one problem recorded for it.

Sources last read 14 September 2026.

Start the diagnosis for this Bay laurel

Bay laurel (Laurus nobilis), the whole plant.
The wub, CC BY-SA 4.0 · Wikimedia Commons

Laurus nobilis is an aromatic evergreen tree or large shrub with green, glabrous (smooth) leaves. It is in the flowering plant family Lauraceae. Wikipedia, CC BY-SA 4.0

Native range: Medit. (subtropical). Also sold as bay, Bay Leaf Tree, Bay Tree, Grecian Laurel, Laurel and Laurel Tree.

What Bay laurel’s sources say that bears on this

Light
Full sun, Partial shade
RHS · read 13 September 2026
Soil moisture
Well-drained
RHS · read 13 September 2026
Humidity
ASHRAE recommends indoor relative humidity between 30% and 60%
Penn State Extension · read 13 September 2026
Pests and diseases
Can be troubled by yellow poplar weevil. Diseases: laurel wilt.
NC State Extension · read 13 September 2026
Can be troubled by tortrix moth, soft scale, horse chestnut scale and bay sucker. Diseases: a leaf spot, powdery mildews and, rarely, honey fungus.
RHS · read 13 September 2026

How this shows up on a Bay laurel

Washed-out patches that do not spread to the shaded side

Affected tissue goes pale and then papery, and the boundary follows where the light falls rather than the shape of the leaf.

Its source names full sun, partial shade, yet a leaf grown in lower light has thinner tissue than one grown in sun, and it scorches if moved into strong light in one step.

Telling it apart: Which side. Damage confined to the lit side is light; damage spread evenly is not.

RHS · read 13 September 2026

Possible causes, likeliest first for a Bay laurel

  1. Most likely spider mites

    Why: Spider mites feed on individual leaf cells, and each emptied cell shows as a pale speck.

    What to try:

    • Move the bay laurel away from other plants.
    • Wash the leaves, top and underside, with a strong spray of water in a shower or sink.

    What would settle it: Hold a sheet of white paper under a leaf and tap the leaf. Tiny specks that move across the paper are mites.

    Check this with the questions

  2. Most likely powdery mildew

    Why: A white coating that wipes off is the surface growth of a fungus.

    What to try:

    • Remove the worst-affected leaves.
    • Improve air movement around the bay laurel and space it away from others.

    What would settle it: Wipe a patch. Powdery mildew comes away and leaves a yellowed patch beneath. White that does not wipe off is part of the leaf, or a mineral deposit from hard water.

    Check this with the questions

  3. Most likely thrips

    Why: Thrips rasp the leaf surface and drink what leaks out, which leaves silvery, papery streaks.

    What to try:

    • Move the bay laurel away from other plants.
    • Wash the leaves thoroughly and remove badly damaged ones.

    What would settle it: Tap a leaf over white paper. Thrips are slender, fast-moving and about the size of a comma; they are easy to see once they are on paper.

    Check this with the questions

Less likely for a Bay laurel, still possible

Questions

What usually causes spots on the leaves on a Bay laurel?
For Bay laurel: most likely spider mites, most likely powdery mildew and most likely thrips.
How can I tell which one it is on my Bay laurel?
What do the marks look like? Pale, dry, bleached patches on the side facing the window; Brown or black spots, many with a yellow ring around them; Tiny pale speckles all over, sometimes with fine webbing underneath; A white powdery coating that wipes off; Silvery streaks with tiny black dots; Dark, soft, water-soaked patches.
What do Bay laurel's sources say about its light?
RHS: Full sun, Partial shade.
What does this look like on a Bay laurel?
Affected tissue goes pale and then papery, and the boundary follows where the light falls rather than the shape of the leaf. Telling it apart: Which side. Damage confined to the lit side is light; damage spread evenly is not.
Is Bay laurel safe to handle while I check it?
Its sources list it as toxic to cats and dogs. Wash your hands after handling the roots or sap, and keep trimmings away from pets.

Something else wrong with the Bay laurel?

Everything the sources say about Bay laurel

What this does not cover

This page orders a decision tree's results using a plant's sourced care. It has not seen your plant, its pot or its window, and two problems at once are common: that is the usual reason a confident answer turns out wrong. The questions in the diagnosis tool narrow it further than a list can.