Why Are My Plant's Leaves Falling Off?

Few things panic a plant owner faster than a carpet of fallen leaves. The good news: leaf drop is a symptom with a short list of causes. Some of it is completely normal; the rest almost always traces back to a recent change in the plant's environment. Here's how to work out which is which.

First, is it actually a problem?

Plants shed their oldest leaves as a matter of course. If you're losing the occasional lower leaf — it yellows slowly, then drops — while the top of the plant keeps pushing out healthy new growth, that's normal senescence and nothing to fix. Worry when leaves fall fast, in numbers, from the top and centre of the plant, or while they're still green.

1. Shock from a change (the usual suspect)

Plants are creatures of habit. Moving to a new room, coming home from the shop or garden centre, being repotted, or even being rotated into very different light can all trigger a wave of dropped leaves as the plant re-balances to its new conditions. This is especially common with fussy species like fiddle-leaf figs and crotons. The fix is patience: settle it in one good spot and stop moving it. New growth usually appears within a few weeks.

2. Watering — too much or too little

Both extremes cause leaf drop. Overwatering suffocates and rots the roots, so the plant sheds leaves it can no longer support; the giveaway is soggy soil, yellowing, and sometimes a sour smell. Underwatering leaves the soil bone dry and the leaves crisp, curl, and fall. Check the soil with your finger before deciding — the symptoms look similar but the fixes are opposite.

3. Temperature swings and cold draughts

A blast of cold air from a window, a door, or air conditioning — or heat from a nearby radiator — is a classic cause of sudden drop, particularly for tropical plants. Keep plants away from draughty spots and heat sources, and don't let them touch cold winter windowpanes.

4. Too little light

When a plant isn't getting enough light to support all its foliage, it drops the leaves it can't afford to keep — usually the lower and innermost ones. If leaf drop came after moving somewhere darker, or as the days shortened in autumn, low light is the likely culprit. Move it closer to a window or add a grow light.

5. Low humidity

Dry indoor air, especially once the heating comes on, stresses humidity-loving plants like calatheas and ferns into dropping leaves after the edges brown. Grouping plants together or running a humidifier helps.

6. Pests

Sap-sucking pests — spider mites, thrips, scale, and mealybugs — weaken a plant until leaves yellow and fall. Check the undersides of leaves and the leaf joints for fine webbing, tiny moving specks, or sticky residue, and treat promptly.

A quick diagnostic

How to stop leaf drop

• Identify the one thing that changed recently, and reverse it if you can.
• Check soil moisture before every watering — feel, don't guess.
• Move the plant away from draughts, radiators, and cold glass.
• Give it stable, bright indirect light and leave it there.
• Inspect for pests and treat at the first sign.
• Then be patient — most plants recover once conditions are steady.

Warning: resist the urge to fix everything at once. Repotting, moving, feeding, and changing the watering all in one week piles on more stress. Change one variable, then wait and watch.

Not sure whether you're looking at normal ageing or a real problem? Snap a photo in PlantMe — it can identify your plant from a database of 35,000+ species and cross-check the symptoms against 500+ common problems to point you to the likely cause.