GrowingHQ

Brunnera: crisp brown edges around the leaf margin

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

What you are looking at

A band of dry, brittle brown tissue following the outline of the leaf, usually with a sharp boundary against healthy green. It is the part of the leaf furthest from the water supply, so almost anything that interrupts that supply shows here first — which is why the margin itself tells you little and the context tells you everything.

What it is likely to be on brunnera

  1. Draught stress

    Candidate 1very common on this plant
    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Ferns — cultivation
    • Royal Horticultural Society: Hydrangea — cultivation

    Checked 2026-08-13

    Damage from moving air rather than from cold alone: a houseplant beside a door, an opening window or above a radiator loses water faster than it can replace it, and drops leaves or browns at the edges. The tell is that the damage is worse on the side facing the draught.

    Points towards it

    • · the ground is dry and these plants have no reserve for that
    • · the edges go first and stay crisp, because they are furthest from the water supply
    • · a dry root run affects everything above it equally

    Argues against it

    • · the ground is wet, so a shortage of water is not what browned the edges — this rules it out entirely.

    Check this next

    Push a finger a full hand's depth into the soil rather than testing the surface, and do it right against the stem of a wall-planted hydrangea. Wall bases and the ground under mature trees stay dry through rain that soaks everywhere else, which is why these plants brown in a wet summer.

    What to do now

    Soak the root run slowly and thoroughly rather than sprinkling it, then mulch deeply with leafmould or compost while the ground is wet. The browned leaves will not recover — judge whether it worked by whether the new growth stays clean.

    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Watering

    Checked 2026-08-13

  2. Leaf scorch

    Candidate 2very common on this plant
    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Ferns — cultivation
    • Plant Finder — Missouri Botanical Garden: Leaf scorch

    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

    • · the damage is on the exposed side and stops where the shade starts, which drought never does
    • · either the sun got stronger or the plant got moved into it — and a shade plant put in a sunny bed scorches in its first summer
    • · an exposure problem in the open garden

    Argues against it

    • · even browning all round a plant is a root or water problem — the sun only reaches one side of it

    Check this next

    Stand where the plant is at midday and see where the sun falls. Scorch maps exactly onto the lit side and stops at the shade line; anything browning evenly on all sides, lit and unlit alike, is about the roots instead.

    What to do now

    Shade it, move it in autumn, or plant something to shelter it — and water it well in the meantime, because a scorching plant is usually also short of water. Cut the worst fronds or leaves out; they will not green up again, and the plant replaces them from the centre.

    source

    Horticultural consensusmoderate confidence

    No external citation — see the evidence type above.

    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 brunnera

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 brunnera — 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 crisp brown edges around the leaf margin page lists causes across all plants, and the Brunnera profile lists the problems it is prone to.