Calathea Problems
Calathea spp.
Calathea is prized for its striking patterned foliage and nighttime leaf movement. It is demanding — sensitive to tap water, low humidity, cold draughts, and inconsistent watering.
All Calathea Problems
⚠ CriticalCalathea — Root Rot — Pythium & Phytophthora Infection
The plant wilts consistently even when the soil is moist or wet. Lower leaves yellow and drop rapidly, and stems near the soil surface may turn dark brown or black and feel hollow. On inspection, roots are black, slimy, and emit a distinctive fetid odour caused by anaerobic decomposition.
⚠ MinorCalathea — Brown, Crispy Leaf Tips — Low Humidity & Salt Stress
Leaf tips and outer margins turn brown, dry, and brittle. The browning begins at the very tip and progresses symmetrically inward along the leaf margins. Affected tissue is desiccated — sharply distinct from the healthy green centre. In severe cases, entire outer thirds of leaves are brown and paper-thin.
⚠ CriticalCalathea — Spider Mite Infestation — Tetranychus urticae
Fine, stippled yellow or bronze speckling appears on upper leaf surfaces as mites pierce individual cells to feed. Infestations progress to visible webbing beneath leaves and between stems, giving a dusty, silken appearance. Severely affected leaves turn bronze-brown and desiccate. Spider mites thrive in hot, dry conditions and reproduce extremely rapidly — a single female can lay 300 eggs over her lifespan.
⚠ ModerateCalathea — Powdery Mildew — Erysiphe & Golovinomyces spp.
A white to grey powdery coating appears on leaf surfaces, stems, and occasionally flower buds. Unlike other fungal diseases, powdery mildew grows on the surface rather than inside plant tissue, giving it a dusted-flour appearance. Affected tissue may yellow beneath the coating. Unlike downy mildew, it occurs on the upper leaf surface and does not require standing water — in fact, it thrives in dry conditions with high humidity.
⚠ ModerateCalathea — Bacterial & Fungal Leaf Spot — Xanthomonas & Cercospora spp.
Dark brown to black spots with yellow halos appear on leaf surfaces, often water-soaked in early stages. Bacterial spots have irregular margins and a translucent, greasy appearance when held to light. Fungal spots (Cercospora, Alternaria) develop concentric rings with a tan, dry centre. Spots coalesce under humid conditions to form large necrotic patches.
⚠ ModerateCalathea — Interveinal Chlorosis — Iron or Magnesium Deficiency
Leaves develop a characteristic pattern of yellowing between the veins while the veins themselves remain distinctly green. In iron deficiency, this interveinal chlorosis appears on the youngest (newest) leaves first, as iron is not readily mobile in plants. Magnesium deficiency presents similarly but begins on older, lower leaves as magnesium is mobile and translocated to new growth. Affected leaves may eventually turn completely pale yellow or near-white.
⚠ CriticalCalathea — Stem & Crown Rot — Botrytis & Fusarium spp.
The stem near or at soil level turns dark brown to black, becomes soft and waterlogged, and collapses inward. The plant may wilt suddenly despite adequate soil moisture, as vascular transport is interrupted. In Botrytis infections, a grey-brown fuzzy sporulation may be visible on affected stems under humid conditions. Once the crown (growing point at the base) is affected, recovery becomes extremely difficult.
⚠ MinorCalathea — Sun Scorch & Leaf Bleaching — Photooxidative Damage
Irregular pale, bleached, or white patches develop on leaf surfaces exposed to direct sun. Affected areas become papery and dry, often with a sharp boundary between bleached and healthy tissue corresponding to shadow edges. In severe cases, the bleached zones turn brown and necrotic. Damage appears suddenly after a change in position or season — the plant's existing leaves have no photoprotective pigments calibrated for higher light intensity.
⚠ MinorCalathea — Fungus Gnats — Bradysia spp. Larvae in Substrate
Small, dark, mosquito-like flies hover around the soil surface and scatter when the plant is disturbed. The damaging stage is the larvae — tiny translucent maggots with black heads that live in the top few centimetres of moist substrate, feeding on fungi, organic matter, and fine feeder roots. Seedlings and freshly potted cuttings may stall or wilt as their delicate roots are grazed.
⚠ MinorCalathea — Springtails in Substrate — Collembola Bloom
Tiny white or grey specks, around 1 mm long, scatter and hop across the substrate surface and pooled water when disturbed. Springtails feed on decaying organic matter, algae, and fungi rather than living plant tissue, so they rarely cause direct harm — but a sudden population bloom is a clear indicator of a persistently wet, organic-rich substrate. In rare cases of very dense populations, they may graze tender seedling roots.
⚠ CriticalCalathea — Rhizoctonia Damping-Off in Seedlings & Cuttings
Young seedlings and freshly potted cuttings collapse suddenly, with a dark, water-soaked, pinched lesion girdling the stem at the soil line. The tissue above the constriction topples over while still green, and fine brown fungal threads may be visible on the stem base or substrate. Germinating seeds may rot before emerging.
⚠ ModerateCalathea — Cold Draught & Chilling Injury
Leaves develop water-soaked or translucent patches that turn brown or black, often appearing suddenly after a cold night or exposure to a draught. Affected areas may be concentrated on the side facing a window or door, and whole leaves can yellow, blacken, and drop. Tropical aroids show damage at temperatures well above freezing — often below 10–12°C.
⚠ MinorCalathea — Poor Airflow — Weak Stems & Disease Pressure
Plants grown in persistently still air develop weak, soft, elongated stems that struggle to support their own leaves, and a recurring cycle of fungal and bacterial problems. Moisture lingers on foliage and at the soil surface, and the boundary layer of stagnant humid air around the leaves favours mould, mildew, and rot. Growth is generally less sturdy and more disease-prone than in well-ventilated conditions.
⚠ ModerateCalathea — Transplant & Acclimation Shock
A recently purchased, repotted, or relocated plant drops leaves, yellows, or stalls within days to weeks despite reasonable care. The change in light, humidity, temperature, or substrate disrupts the plant's established balance, and Alocasia in particular may shed several leaves while adjusting. The decline is transient if conditions are stable, with new growth resuming once the plant adapts.
⚠ ModerateCalathea — Crinkled New Leaves & Stuck Leaf Syndrome
New leaves emerge crinkled, deformed, or fail to unfurl properly, sometimes tearing or remaining stuck inside the previous sheath. Thin-leaved and velvet-leaved aroids are most affected, and existing leaves may show crisping margins. The cause is typically chronically low humidity, which dries the delicate emerging leaf before it can expand fully.
⚠ ModerateCalathea — Fertiliser Burn — Nutrient Toxicity
Leaf tips and margins turn brown and crispy, often quite suddenly after feeding, and a white crust of fertiliser salts may appear on the substrate surface or pot rim. Roots can be chemically scorched, leading to wilting despite moist soil. The damage results from an excessive concentration of dissolved salts drawing water out of the roots — the opposite of the deficiency it is sometimes mistaken for.
⚠ ModerateCalathea — Salt Crust & EC Build-Up in Substrate
A white or yellowish crust accumulates on the substrate surface, pot rim, and drainage holes, accompanied by browning leaf tips and margins and a general loss of vigour. The build-up comes from dissolved minerals in tap water and fertiliser residue concentrating over time as water evaporates. High substrate salinity (electrical conductivity) impairs the roots' ability to take up water.
⚠ MinorCalathea — Inconsistent Watering — Boom-Bust Cycle
The plant shows a mixture of symptoms — some crispy edges, some yellowing, intermittent wilting, and uneven growth — reflecting alternating periods of drought and saturation. Roots are repeatedly stressed by swinging between bone-dry and waterlogged, never settling into a stable moisture range. Sensitive aroids and Calatheas are especially intolerant of this seesaw.
⚠ ModerateCalathea — Substrate pH Lock-Out
The plant shows nutrient-deficiency symptoms — yellowing, interveinal chlorosis, pale or stunted growth — despite a regular and adequate feeding program. The cause is a substrate pH outside the optimal range, which chemically locks nutrients into forms the roots cannot absorb. Adding more fertiliser fails to help because the nutrients are present but unavailable.
⚠ MinorCalathea — Chlorine & Fluoride Tip Toxicity
Leaf tips and margins turn brown and necrotic, often with a thin yellow band separating the dead tissue from healthy green. The damage accumulates gradually with each watering and is most pronounced on sensitive species that concentrate these elements at the leaf extremities. Unlike low-humidity tip burn, the cause is chemical — chlorine and fluoride in treated tap water.
⚠ ModerateCalathea — Weak Water-Propagated Roots Failing to Transition
A cutting roots well in water but then declines after being potted into substrate — wilting, yellowing, or stalling as the water-formed roots fail to function in soil. Water roots are structurally different from soil roots and often cannot absorb efficiently or survive the change. The plant may sit for weeks without establishing or may rot at the transition.
⚠ ModerateCalathea Leaf Curling — Underwatering, Low Humidity or Heat Stress
Calathea leaves curl inward along their length, forming tight cylinders or tubes rather than lying flat. The rolling is the plant's defensive mechanism to reduce the leaf surface area exposed to transpiration, conserving water when conditions are too dry, too warm, or when the root zone is failing to supply adequate moisture. Curled leaves may still appear green initially but will yellow and crisp if the cause is not addressed promptly.
⚠ MinorCalathea Fading Leaf Pattern — Light Bleaching & Pigment Loss
The distinctive silver, cream, or contrasting markings on Calathea leaves become muted, washed out, or uniformly pale green. New leaves emerge without the pattern definition seen in healthy specimens. The ornamental pigment cells (chromatophores) in Calathea are photosensitive — excessive light bleaches the accessory pigments that create the pattern, while insufficient light causes general chlorophyll dilution.
⚠ CriticalCalathea New Growth Dying — Unfurling Leaves Rotting Before Opening
New leaves emerge as tightly rolled spears but fail to unfurl fully — the tips turn brown and mushy, the leaf sticks together, or the emerging shoot collapses before opening. In severe cases, the growth point itself rots, halting all new growth indefinitely. This condition differs from general tip burn as it exclusively affects developing growth that has not yet unfurled.
⚠ ModerateCalathea — LED Grow Light Burn — Bleaching & Necrosis from Artificial Light
Leaves directly beneath or closest to the LED grow light develop bleached, pale, or white patches — often with brown necrotic zones in the most severely exposed areas. The damage pattern reflects the light distribution of the lamp: typically a central circular zone of maximum bleaching surrounded by a gradient of lesser damage. Unlike sun scorch, grow light burn can occur at any time of year regardless of season and is often gradual rather than sudden.
⚠ ModerateCalathea — Root-Bound Stress — Impacted Root System in Undersized Pot
Roots emerge from drainage holes or wrap visibly around the outer rim of the pot when the plant is removed. The substrate dries out extremely rapidly — sometimes within 24 hours of watering. Growth slows despite adequate fertilisation, and the plant may droop even immediately after watering as the dense root mass prevents adequate water retention. Some species produce smaller-than-usual new leaves as the root system cannot support normal leaf expansion.
⚠ ModerateCalathea — Repotting Shock — Post-Transplant Wilting & Stress Response
Following repotting, the plant wilts, droops, or shows yellowing in the days to weeks after transplanting, despite the substrate being correctly moist. New growth stalls or reverses. In severe cases, previously firm leaves become limp and fail to recover even after watering. Repotting shock occurs because root tip damage during transplanting temporarily reduces the plant's water uptake capacity while the substrate moisture level remains adequate.
⚠ ModerateCalathea — Manganese Deficiency — Young Leaf Interveinal Chlorosis & Pale New Growth
New, young leaves emerge pale yellow or light green, with a distinct interveinal chlorosis pattern where the tissue between veins loses green colour while the vein network remains visible. This mirrors iron deficiency but appears exclusively on the youngest growth — manganese is not mobile in plants and cannot be redirected from older leaves. As deficiency progresses, necrotic brown spots develop within the chlorotic zones.
⚠ MinorCalathea — Chloramine Water Toxicity — Tip Burn Resistant to Standard Fixes
Persistent brown leaf tips and margins that do not resolve after switching to filtered water or leaving water to stand overnight. Unlike chlorine toxicity (which off-gasses within 24 hours), chloramine is a stable compound that cannot be removed by simple standing or aeration. Most modern municipal water treatment now uses chloramine rather than free chlorine — plants sensitive to halide compounds continue to show tip burn even when the grower believes they have addressed the 'chlorine problem'.
⚠ CriticalCalathea — No Drainage Hole — Root Rot from Standing Water Accumulation
The plant wilts despite being recently watered, with the substrate appearing moist on the surface but waterlogged at the base. Leaves yellow progressively from the lower growth upward. A sour smell may be detectable from the substrate. These are the classic presentation of root rot in a pot without drainage — excess water that cannot escape accumulates at the base and creates an anaerobic zone where Pythium, Phytophthora, and Fusarium establish rapidly.
⚠ ModerateCalathea — Winter Overwatering — Seasonal Watering Frequency Mismatch
Tropical houseplants show yellowing, mushy stems, or root rot symptoms in autumn and winter despite an apparently correct watering schedule maintained from the summer period. The cause is seasonal: as day length shortens and temperature drops, plant metabolism, photosynthesis, and water uptake all decline significantly — but the grower continues watering at the same summer frequency. Water that was absorbed in days during active summer growth now sits in the substrate for weeks.
⚠ MinorCalathea — White Mineral Deposits on Leaves — Hard Water Calcium & Magnesium Residue
White, chalky, or powdery deposits appear on the upper surface of leaves, typically after misting, overhead watering, or in hard-water areas with high calcium and magnesium content. The deposits are not mould or a disease — they are mineral salts left behind when water droplets evaporate. While not directly harmful to leaf tissue, heavy mineral deposits reduce photosynthetic efficiency by blocking light penetration and can cause physical leaf damage when rubbed abrasively to remove them.
⚠ MinorCalathea — Humidity Tray Mould — Stagnant Water Breeding Fungus Gnats & Mould
White or grey mould grows on the pebbles or water surface of a humidity tray placed beneath the plant. Fungus gnat populations increase near the plant. A musty smell develops. While humidity trays can be effective tools for raising local RH, the standing water becomes a breeding site for fungus gnats (Bradysia spp.) and supports the growth of various moulds that can spread to the substrate surface and cause soil-level issues.
⚠ ModerateCalathea — Pothos Spider Mites — Fine Webbing and Stippled, Pale Leaves
Leaves develop a fine bronze or silver stippled pattern — thousands of tiny pale dots where mites have pierced the leaf cells. Fine silken webbing appears between leaves and stems, particularly at the growing tip. In heavy infestations the webbing may cover the entire plant. The plant's overall vigour declines rapidly. Spider mites (Tetranychus urticae and relatives) are not insects but arachnids — they are not killed by insecticides and require specific miticides or contact treatments. They thrive in hot, dry indoor conditions and can complete a full life cycle in 7 days at 30°C.
⚠ MinorCalathea — Pothos Leaf Curling — Dehydration Stress, Cold & Root Restriction
Leaves curl inward along their length (edges rolling toward the midrib) or droop and curl downward. The plant looks thirsty but may not respond normally to watering. Leaf curling in Pothos is a water conservation response — by reducing the exposed leaf surface area, the plant slows water loss through transpiration. Unlike wilting (which is more extreme), curling indicates the plant is under stress and self-regulating before the situation becomes critical.
Calathea Care Guide
Light, watering, humidity, fertilising, repotting and propagation — everything you need to keep your Calathea thriving.
Full care guide →See how growers fixed these problems
Browse real Calathea grow diaries from the community — treatments, timelines, and results.
Browse community diaries →Common Calathea Questions
Why are my Calathea leaves curling?
The plant wilts consistently even when the soil is moist or wet. Lower leaves yellow and drop rapidly, and stems near the soil surface may turn dark brown or black and feel hollow.… Read the full guide →
Why do my Calathea leaves have brown tips?
Leaf tips and outer margins turn brown, dry, and brittle. The browning begins at the very tip and progresses symmetrically inward along the leaf margins. Affected tissue is desicca… Read the full guide →
Why is my Calathea turning yellow?
Fine, stippled yellow or bronze speckling appears on upper leaf surfaces as mites pierce individual cells to feed. Infestations progress to visible webbing beneath leaves and betwe… Read the full guide →
How often should I water my Calathea?
A white to grey powdery coating appears on leaf surfaces, stems, and occasionally flower buds. Unlike other fungal diseases, powdery mildew grows on the surface rather than inside … Read the full guide →
