Greenie Get the app Yellow leaves
Why are my plant's leaves turning yellow?
Too much water is the most common reason houseplant leaves turn yellow: soggy soil starves the roots of air, so lower and inner leaves yellow and droop. Let the soil dry to the depth the plant likes, make sure the pot drains and empty the saucer. If the soil is dry instead, or only one old leaf is yellow, look at thirst, light, cold or feeding.
Check these first
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Push a finger a few centimetres into the soil. Wet soil with yellow leaves points to overwatering; bone-dry soil points to thirst.
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Note which leaves are yellow. Old and new leaves yellowing together suggests too much water; only the oldest, lowest leaves usually means drought, age or hunger; pale new leaves with green veins suggest an iron problem.
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Lift the pot and check the bottom. Is there a drainage hole, and is water standing in the saucer or cover pot?
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Slide the plant out and look at the roots. Firm, pale roots are healthy; dark, soft roots mean rot; dry, brittle roots mean it has been left dry too long.
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Think about where it stands: a dim corner, a cold draughty window, hot direct sun, or a recent move.
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Look for white crust on the soil or pot rim and check leaf undersides for tiny pests or fine webbing.
Causes and fixes
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Overwatering or poor drainage
How to tellThe soil stays damp for days, several leaves yellow at once, often lower and inner ones first, and they feel soft rather than crisp. In bad cases the stem base softens and the roots are dark and mushy.
What to doStop watering until the top of the soil has dried to the depth the plant's care sheet gives. Empty saucers and cover pots after every watering. If the roots are dark and soft, cut them off and repot in fresh mix in a pot with a drainage hole, no bigger than the root ball needs.
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Underwatering
How to tellThe soil is dry and has often shrunk from the pot edge, the plant wilts, and the oldest leaves yellow and drop first, often with crisp brown tips or edges.
What to doWater slowly until it runs out of the drainage hole. If the mix has dried hard and water runs straight through, stand the pot in a bowl of water until the surface is moist, then let it drain. Check the soil more often from then on instead of watering on a fixed day.
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Too little light
How to tellThe plant sits far from a window, growth is thin and stretched, new leaves are small and pale, and lower leaves slowly yellow and fall.
What to doMove it closer to a bright window, or add a grow light, keeping to the light its care sheet asks for. Water less while it recovers, since a plant in poor light uses little water.
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Cold, draughts or a sudden change
How to tellYellowing or leaf drop follows a move, a cold night by the glass, or a spot next to a door, air conditioner or heater.
What to doKeep the plant in one steady spot away from draughts, heaters and cold window glass in winter. Expect it to drop a few leaves after a move and avoid moving it again.
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Hunger or a nutrient problem
How to tellThe plant has been in the same mix for a long time or is pot-bound and the older leaves turn evenly pale yellow (often nitrogen). On acid-loving plants watered with hard water, the newest leaves yellow while the veins stay green (iron).
What to doFeed with a balanced houseplant fertilizer during the growing season at the rate on the label, and repot a crowded plant in spring. For acid-lovers such as gardenia, repot into ericaceous (lime-free) mix, water with rainwater and give a dilute liquid feed sprayed onto the leaves.
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Too much fertilizer or salt build-up
How to tellA white crust forms on the soil or pot rim, leaf tips and edges brown, and lower leaves yellow and drop even though watering is right.
What to doScrape off any crust, then flush the pot with plenty of plain water, at least twice the pot's volume, and let it drain completely. Feed less often afterwards, and flush the pot before a feed rather than after, so you do not wash the fertilizer straight out.
Stop it coming back
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Water by checking the soil, not by the calendar, and water less in winter.
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Use pots with drainage holes and never leave the plant standing in water.
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Give each plant the light its care sheet asks for and keep it away from draughts and heaters.
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Feed only in spring and summer, and flush the soil with plain water every few months.
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Repot into fresh mix when roots fill the pot, going up only one size.
When to worry
When to worry
One old leaf at the bottom yellowing and dropping now and then is normal ageing, and so is a little yellowing after a move. Worry when many leaves yellow at once, when new leaves turn yellow too, or when the stem feels soft or the soil smells sour: that usually means root rot. Unpot the plant, cut away dark, mushy roots, and repot what is healthy in fresh, free-draining mix; if the stem base is rotten, root healthy cuttings instead.
