GrowingHQ

Strawberry: spreading brown or black patches on leaves and stems

2 causes GrowingHQ holds specifically for strawberry, what separates them, and what is safe to do before you are sure.

What you are looking at

Dark, water-soaked-looking lesions that enlarge over days, often with a pale halo, sometimes with a white fuzz on the leaf underside in damp weather. On potatoes and tomatoes in a wet summer this is the sign that matters most.

Described view

Strawberry foliage and fruit in one frame: a berry and adjoining leaf tissue carrying the dense grey-brown fur of botrytis with the tissue beneath collapsed, and separately a leaf with dry, sharply-edged brown scorch along the margin and between the veins with no fungal growth on it at all

What it is likely to be on strawberry

  1. Grey mould

    Candidate 1very common on this plant
    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Grey mould

    Checked 2026-08-13

    Soft fruit turning brown and collapsing under a fuzzy grey coat, often overnight in wet weather. It is the single biggest cause of strawberry losses in a wet British summer, and it infects at flowering rather than when the mould appears.

    Points towards it

    • · a soft grey furry coating over the damage is the identification
    • · botrytis needs prolonged wetness and still air
    • · worst in a wet summer and in an unventilated tunnel

    Argues against it

    • · dry conditions and good airflow make botrytis very unlikely

    Check this next

    Look at the fruit rather than the leaves. Grey mould turns a ripening strawberry into a dull brown fruit covered in grey fur, often overnight, and it spreads from fruit to touching fruit — that contact spread is the signature.

    What to do now

    Pick off and bin every affected fruit and leaf as soon as you see it, rather than leaving it in place, and do not compost it. Straw or a mat under strawberries keeps the fruit off wet soil, which prevents far more of it than anything applied afterwards.

    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Grey mould — control

    Checked 2026-08-13

  2. Leaf scorch

    Candidate 2common on this plant
    source

    Sourced guidancemoderate confidence

    • Royal Horticultural Society: Heat and drought stress

    Checked 2026-08-13

    Dry, brown, brittle patches or margins where tissue has died, typically on the side facing the light and on the most exposed leaves. Unlike a disease it does not spread, and unlike drought it affects the exposed leaves rather than the whole plant.

    Points towards it

    • · scorch follows hot sun on a plant that could not keep up with water loss
    • · dry soil is what turns strong sun into scorch

    Argues against it

    • · grey fur over the damage is botrytis, which is a fungus rather than sun damage — this rules it out entirely.

    Check this next

    Look for fur. Grey mould covers the damage in a soft grey coating and spreads from fruit to touching fruit; scorch is dry, papery and brown, appears on the most exposed leaves after a hot spell, and does not spread from one fruit to the next.

    What to do now

    Water at the base in the early morning and mulch to keep the roots cool. Do not water over the foliage to cool it — wet leaves in a strawberry bed invite exactly the grey mould this is being distinguished from.

    source

    Sourced guidancemoderate confidence

    • Royal Horticultural Society: Heat and drought stress

    Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Work through it for your strawberry

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on strawberry — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general spreading brown or black patches on leaves and stems page lists causes across all plants, and the Strawberry profile lists the problems it is prone to.