cold damage

Symptoms

Soft brown-black patches on leaves the morning after a cold night, no progression once warm, leaves do not recover but plant survives.

Plants affected

• snake plant

Easily confused with

• overwatering / root + rhizome rot

  How to tell them apart: Both cold damage and overwatering on snake plant (Sansevieria trifasciata) cause soft, mushy, water-soaked tan-brown collapsing tissue, so the mush itself is not diagnostic. Cold damage appears suddenly after a cold night or cold-window draft, starting at the leaf TIPS and exposed outer faces as translucent, scarred, sunken patches that later turn pale brown/tan and papery, while the soil and roots stay normal. Overwatering instead starts at the leaf BASE and soil line, where leaves go soft, yellow and floppy and pull away easily, with a foul rotten smell and dark slimy roots in soggy soil. Check the base and roots and recent temperatures: rot from the bottom in wet soil = overwatering; sudden tip/face damage after cold with dry healthy roots = cold injury.

• Fusarium leaf spot

  How to tell them apart: Cold (chilling) damage on Sansevieria trifasciata appears soon after a cold spell as diffuse, soft, water-soaked patches that turn pale tan to dark brown anywhere on the leaf — often broad, sunken and mushy at the leaf base or along the side that faced the cold window, with no defined margin and no fungal structures. Fusarium leaf spot (Fusarium moniliforme) instead starts as small reddish-brown sunken spots, mainly on young/new growth, that enlarge into oval lesions with a distinct reddish-tan margin and a yellow (chlorotic) halo, frequently appearing after overhead watering or in warm humid conditions. Key tells: cold damage is a one-off broad blotch tied to a cold event with no halo, while Fusarium spots are multiple, smaller, halo-ringed and spread/multiply over time in warmth and wetness.

Common questions

How do I recognise cold damage on snake plant?

Soft brown-black patches on leaves the morning after a cold night, no progression once warm, leaves do not recover but plant survives.

Do I have to report cold damage?

No. cold damage is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is cold damage treated?

With a sequence of steps whose timing matters as much as the choice of product — and both depend on the plant, the season and your country. Dr. Phyto works them out in a free diagnosis.