Leaf scorch and sunburn appear as bleached, tan or brown crispy patches on the parts of a plant that take the most light and heat — and they very often appear suddenly, after a change: a houseplant moved to a sunnier window, plants set outside in spring, or a heatwave. It is physical damage, not an infection, so it does not spread from leaf to leaf once you remove the cause, and the damaged tissue will not recover.
The short answer
Bleached white-to-brown crispy patches on the most exposed, sun-facing leaves mean too much direct light and/or heat for a plant that was not acclimatised to it. Move the plant to gentler light or provide shade, keep it well watered, and introduce plants to strong sun gradually rather than all at once.
How to identify it
Scorch is located where the light and heat hit hardest — the top and sun-facing leaves, not the shaded interior; it is dry and crisp rather than soft; and it stops advancing once the plant is moved. Spreading spots, yellow haloes, concentric rings or pests on the undersides indicate disease or infestation instead — compare leaf spot and yellow leaves.
Sunburn from a sudden increase in light
Leaves grown in lower light have thinner tissue and fewer protective pigments; thrown into direct sun they bleach and burn within a day or two. This is why plants moved to a brighter window, or houseplants and seedlings put outdoors in spring without hardening off, scorch so readily. Acclimatise over 1–2 weeks — a little more direct light each day — and match plants to the right exposure using light requirements for houseplants.
Heat and wind scorch
Even sun-adapted plants scorch when heat and dry wind pull water from the leaves faster than the roots can replace it, drying edges and tips. It is worst on under-watered plants, plants in small pots that overheat, and foliage against hot glass or masonry. Keep plants well watered in heat (see watering) and shelter them during extremes — see protecting plants from heat and sun; outdoors, shade cloth during the hottest hours prevents it.
The role of water
A well-hydrated plant resists scorch far better than a dry one, because transpiration cools the leaf. Water at the base early or late in the day; avoid wetting foliage in strong sun, where droplets can intensify the light and leave spot burns, and where a mid-heat drench can shock roots.
What to do now, and what not to do
Move the plant out of the harsh light or provide shade, water it well, and trim badly damaged leaves for appearance once new growth is underway. Do not assume the crisp patches mean the plant is thirsty for far more water — the issue is exposure, not chronic drought — and do not keep a freshly relocated plant in full sun “to toughen it up,” which simply burns more leaves.
Recovery, prevention and exceptions
Scorched tissue is dead and will not green up; recovery shows as healthy new leaves adapted to the brighter spot. Prevent it by acclimatising plants to any increase in light, hardening off before moving outdoors, watering well in heat, and shading vulnerable plants at midday. Exceptions worth knowing: many low-light foliage plants (calatheas, marantas, ferns, pothos) scorch in any direct sun and belong in bright indirect light, whereas succulents and cacti tolerate sun but still sunburn if moved abruptly from indoors to full outdoor sun. Related: brown leaf tips.
Quick diagnostic logic
- Bleached/brown crispy patches on top and sun-facing leaves, appeared after a move to brighter light → sunburn from no acclimatisation.
- Brown dry edges after a heatwave or against hot glass, plant a bit dry → heat/wind scorch; water and shade.
- Spots that spread, have yellow haloes, or appear on shaded leaves too → not scorch; look at disease or pests.
- Interior/lower leaves fine, only the exposed layer damaged → confirms light/heat, not a root or watering fault.
Glass, reflected heat and water droplets
Window glass concentrates heat and can magnify sun onto nearby foliage, so a plant that is fine on a shaded sill can scorch on a south- or west-facing one in summer — sheer curtain diffuses it. Pale walls, paving and glasshouse staging reflect extra heat and light onto plants below. Water droplets sitting on leaves in strong sun can also focus light into small burn spots, which is one reason to water at the base and in the cooler part of the day.
Which plants scorch easily, and which tolerate sun
Thin-leaved, shade-adapted foliage plants — calatheas, marantas, ferns, pothos, peace lilies, many philodendrons — scorch in any direct sun and want bright indirect light. Variegated plants scorch more readily than their all-green forms because the white areas lack protective pigment. Succulents, cacti, pelargoniums, olives and Mediterranean herbs tolerate strong sun once established, but even they burn if moved abruptly from indoors to full outdoor sun without hardening off. See light requirements for houseplants.
Trimming and recovery
Scorched tissue is dead; the leaf will not repair, though a lightly marked leaf can be left to keep working. Trim badly disfigured leaves once healthy new growth is established, and reposition the plant so the new leaves develop in appropriate light. Recovery is simply the plant producing undamaged leaves in a better spot.
Related plant problems
◀ Back to the Plant Problems hub to diagnose by symptom, pest or disease.
- Why leaves turn yellow
- Brown leaf tips and edges
- Wilting and drooping
- Transplant shock
- Leggy growth (etiolation)