A pale, papery patch on a leaf that was fine last week is alarming. If the plant was recently moved, it often points to scorch. The RHS says plants usually grow out of it. The damaged patch itself will not recover, so the job is to find the cause and stop it spreading.

Scorch has two drivers that often act together. University of Maryland Extension says strong sun and heat break down chlorophyll in the leaf. The RHS adds that scorch happens whenever leaves lose water faster than the roots can replace it.

What sunburn and scorch look like

SignWhat the sources say
Pale, bleached or faded areasFirst sign of excess light; they later turn brown and brittle (Maryland)
Bleached or scalded leaves, sometimes dyingOften after a plant is moved outdoors into direct light (Clemson HGIC 1450)
Damage on the sunny side onlyLower leaves, inner leaves and the shaded side are spared (RHS)
Brown upper leaves on a shade plantA sign the plant is in too much light (RHS)
Yellowing, smaller new leaves, leaf dropChlorophyll destroyed by light above the plant’s optimum; large brown dead patches are called leaf scorch (NC State)
Brown, dry leaf marginsTissue farthest from the main veins dries out first (Colorado State)

Maryland notes that symptoms are more severe when strong sun is combined with dry soil. Iowa State gives the same overall rule: if leaves are bleached or damaged, or turn yellow or brown and drop, light levels may be too high.

Why moved and repotted plants scorch

The light jump is bigger than it looks

Leaves adjust to the light they grow in. NC State explains that acclimatization lets plants modify their leaf cell structure to the light, humidity and fertilizer of a new spot. A sudden jump skips that adjustment.

Clemson HGIC puts numbers on the gap. A well-lit home interior is often under about 1,100 lux (100 foot-candles). Outdoors on a clear day it can exceed about 108,000 lux (10,000 foot-candles). Iowa State says even the brightest indoor spot gets only a fraction of the light of a shady spot outside.

That is why the classic case is a houseplant put straight into the garden. Iowa State warns that leaf burn, discolouration and drop can follow. On succulents the damage to fleshy stems and leaves is permanent.

Indoor moves count too. The RHS says strong summer sun can scorch susceptible plants through glass. Clemson’s end-of-winter advice is to raise light gradually when moving low-light plants closer to windows in spring. NC State adds that sun through a window can heat tender tissue, and that plants left in direct sun in a parked car can burn.

Root loss makes leaves more vulnerable

Colorado State University Extension says leaf scorch most often comes from a root system that cannot meet the plant’s needs. Its causes include root loss, drought, overwatering and too much fertilizer. Root loss of any kind counts, so a plant whose roots were trimmed or torn in a repot has less capacity to keep up with water loss in strong sun.

Pot-bound plants have the same problem from the other direction. Maryland says water runs through a pot-bound root ball too fast, leaving the centre dry, and leaves show tip dieback or browning.

Iowa State’s advice for summer outdoors fits this: repot a few weeks before the move, not on the day.

How to acclimate a plant to brighter light

Every source agrees on the principle. Clemson HGIC 1450 says any change in light intensity should be gradual. The details differ:

SourceMethod
University of Maryland ExtensionStart with 2 hours of full sun a day, then gradually lengthen it
Iowa State ExtensionMove to full shade outdoors first, then add more light over 10–14 days. Never move straight into full sun
University of Illinois ExtensionNo direct sun. A few hours outdoors on the first day, more each day, ready in 1–2 weeks
Clemson HGIC 1454A few days in deep shade under a tree, then gradually brighter. Plants moved straight into direct sun will burn
NC StateStart in shade and move into higher light gradually, if the plant needs it

Many houseplants never need full sun. Iowa State says many can stay in full shade all summer. Clemson says most succulents and cacti tolerate full sun, while foliage plants belong in heavy to light shade.

NC State applies the same rule indoors: acclimatize plants when you switch to brighter grow-light bulbs.

Sunburn, salt burn or cold damage?

These three get confused because all of them brown leaves. Check the pattern and the recent history.

CausePatternOther clues
SunburnBleached, pale or tan patches on the exposed side; later brown and brittleRecent move, brighter window, or dry mix (Maryland, RHS)
Fertilizer or salt burnBrowning or dieback of leaf tips and margins, all around the plantWhite crust on mix or pot rim, lower leaf drop, dead root tips (Maryland, Clemson)
Cold injuryBlackening of leaves or shoots; severely chilled leaves look water-soakedExposure below 10 °C (50 °F); symptoms can keep appearing for up to a week (Maryland), or weeks later after mild chilling (NC State)
Cold-water spottingWhite or straw-coloured spots or patchesWatering with cold water or splashing leaves (Clemson, RHS)
DroughtWilting and browning at the top of the plant, or whole leaves browning and fallingDry, light pot (RHS)

Two extra clues from the RHS: water droplets on hairy leaves can focus sunlight and leave burnt spots, while smooth leaves are rarely affected. Leaf shine and insecticide aerosols can also leave pale spots on exposed surfaces.

If the browning is at the tips on every side, read our fertilizer schedule for how to flush salts.

What to do about scorched leaves

  1. Move the plant back to shade or bright indirect light, then reintroduce light slowly using one of the methods above.
  2. Check the mix. Maryland says dry soil makes scorch worse. Water thoroughly if it is dry, and check the roots if it is wet.
  3. Leave the damage or trim it. Colorado State says scorched tissue will not turn green again. The RHS says the plant usually grows out of it and you can prune out badly damaged growth.
  4. Trim lightly damaged leaves. If less than a third of a leaf is damaged, NC State suggests trimming off the dead part but leaving a sliver of brown, so the cut edge does not keep dying back.
  5. Remove badly damaged leaves where they attach to the stem (NC State).

Plant-specific guides

We have written guides for the plants that scorch most often indoors:

For when to move plants by season, see our houseplant care calendar.

References