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Notebook · Guide 8 October 2026 · houseplants

Lemon trees in winter: why the leaves drop and what to do

Bring lemons in as autumn nights cool. Give them a bright, cool, steady spot, water sparingly with tepid rainwater and use winter citrus feed. Warmth, draughts and wet roots cause leaf drop.

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You brought your lemon tree in for winter, and within a few weeks it's dropping leaves onto the carpet. This is the most common lemon complaint in Britain, and the RHS's answer is consistent: draughts, temperatures too low or too high, swings between the two, dry air, and usually too much water as well. A lemon wants a cool, bright, steady winter. A warm, dim living room next to a radiator is close to the worst place for it.

01At a glance

  • When to bring it in: as soon as night temperatures start to dip in autumn, well before the first frost.
  • Where: the brightest cool spot you have, such as a conservatory, porch or frost-free greenhouse. Lemons keep their leaves in winter and need plenty of light.
  • How cold: nights no lower than about 10°C, the RHS minimum for lemons.
  • Water: sparingly, with tepid rainwater. The RHS warns against overwatering in winter.
  • Feed: a winter citrus feed from November to mid-March.

02Bringing it in

The RHS says citrus must come indoors as soon as night temperatures start to dip in autumn. Don't wait for a frost forecast.

  1. Check it over first. Look under the leaves and along the stems for scale insects (small, shell-like bumps), mealybug and the fine speckling of red spider mite. It's easier to deal with them now than in a warm room in January.
  2. Choose the spot before you move it. You want maximum light and a cool, even temperature. A conservatory or bright porch is ideal. If it has to be indoors, use the brightest window in the coolest room, away from radiators and outside doors.
  3. Move it once, and leave it there. Repeated moves between warm and cold rooms are exactly the temperature swings that cause leaf drop.

03How cold is right?

The RHS gives two figures on different pages. Its citrus growing guide says some lemons will be fine as low as 5°C. Its citrus problems page says lemons need a winter night minimum of "not less than 10°C". We follow the stricter figure: keep nights at 10°C or above. The RHS also notes that most citrus "prefer a cool spell in winter". A cool spot is what it needs. The heat is the problem, not the cure.

04Winter watering and feeding

  • Let the compost surface partly dry, then water thoroughly with tepid rainwater and let it drain. This is the RHS method.
  • Err on the dry side. The RHS warns against overwatering in winter, and says the first sign of root rot may be leaf fall or yellowing.
  • Never leave the pot in a saucer of water.
  • Switch feeds: summer citrus feed from March to October, then a winter citrus feed from November to mid-March. The RHS says citrus keep their leaves all winter and benefit from feeding all year round. Yellowing leaves can also mean under-feeding.
  • Raise the humidity with a tray of gravel or clay pellets under the pot, the water kept just below the surface. Dry air is on the RHS list of leaf-drop causes.

05Why is my lemon dropping leaves?

  • Leaves dropping soon after coming in: the change of temperature and light, made worse by a warm, dim room. Find a cooler, brighter spot and keep it there.
  • Yellowing, then dropping, with wet compost: overwatering. Let it dry more between waterings. Check the roots if it keeps happening.
  • Drop near a door or a radiator: draughts or temperature swings.
  • Mottled leaves, falling early: red spider mite. The RHS says it causes mottled leaves, and heavy attacks can make leaves dry up and drop. Look underneath with a hand lens.
  • Sticky leaves, black sooty patches: soft scale insects, which the RHS says produce large amounts of sticky honeydew. Check for mealybug at the same time.

Whatever the cause, keep conditions steady and don't overwater to "help". A stressed tree with wet roots is the one that goes downhill.

06Putting it back out

The RHS says to move citrus out to a sunny, sheltered spot once the weather allows. Watch the overnight temperatures, as you may need to wait until mid-June, and harden it off gradually so the change doesn't check its growth.

Save your money
Don't buy a heater for it. Lemons want cool, not warm. A bright, unheated but frost-free space does the job.
Don't feed more to fix leaf drop. Use the right seasonal feed at the label rate. More feed won't cure a draught or wet roots.
Collect rainwater. It's free, and it's what the RHS recommends, at room temperature.
Don't rely on a mister. The RHS's humidity advice is a gravel tray under the pot. Where it mentions misting, it says to do it early in the morning in summer.

Before placing a lemon tree where children or pets can reach it, check the safety flags on our lemon tree profile.

How we checked this

Every care and safety claim on this page is verified against horticultural and veterinary sources.

Sources: RHS — How to grow citrus · RHS — Citrus: problems · RHS — Glasshouse red spider mite

Checked 8 October 2026. If our advice ever conflicts with the RHS, believe them and tell us.