Lemon

Lemon: how do you recognise it?

Habit

Small tree or shrub; in a pot usually 1–2 m tall, often with thorns on the twigs.

Leaves

Oval, leathery and glossy green, 5–10 cm; they smell of lemon when rubbed.

Flower

White, tinged purple on the outside, 3–4 cm, strongly scented. Mainly in March–June, often later too.

Fruit

Oval and yellow when ripe. Ripening takes six to nine months, sometimes longer.

Roots

Fairly shallow and sensitive to waterlogging and hard, limy water.

Flowering: March–June · Harvest and fruit: December–April · Plants: April–May · Pruning: March

Why grow it?

• Fragrant flowers that fill a whole patio with their scent.
• Your own lemons, to pick whenever you need them.
• Glossy evergreen leaves: an attractive container plant all year.
• Flowers, green fruits and ripe fruits often hang on the tree at the same time.
• Brings a Mediterranean feel to a sunny patio or balcony.

Lemon: where does it grow best?

• From May to October outdoors in the sunniest, warmest and most sheltered spot on the patio.
• In a pot with citrus compost or an open, slightly acid potting mix; it must drain freely.
• Normally moist: the top of the compost may dry out between waterings, but it must never dry out completely.
• Sheltered from wind and heavy rain, which knock off flowers and young fruits.
• In winter, indoors somewhere light and cool, at 5–12 °C.

Light

Sun

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

2.5 m tall, 1.5 m wide

Hardiness

Half hardy (to -3 °C): protect it in harsh winters

Goes well with

• Olive: Another Mediterranean container plant for the same sunny patio.
• Bay: Evergreen, does well in a pot and also likes a cool winter.
• Lavender: Scented and bee-friendly, at the foot of the pot or in a trough nearby.
• Rosemary: A Mediterranean herb that copes with the same sun and dry air.

Lemon: when and how to plant it?

Plant in April–May.

1. Repot in April or May, before it goes outside.
2. Choose a pot only a few centimetres wider than the last, with a drainage hole and a layer of gravel or clay pebbles at the bottom.
3. Use citrus compost or potting compost with some sand and fine gravel, so water drains away well.
4. Set the plant at the same depth as before: the graft union must stay well above the compost.
5. Water with rainwater until it runs out of the bottom of the pot, then let it drain well.
6. Let it get used to the outdoors for a week in partial shade before it goes into full sun.

Care

Water

Water when the top 2–3 cm feels dry, preferably with rainwater or soft water. Never leave water standing in the saucer. Much less in winter.

Feeding

From April to September, citrus feed every one to two weeks. In winter, none or very little.

Repotting

Every two to three years in spring. For older plants in a large pot, just replace the top layer of compost.

Overwintering

Bring it in before the first frost, to a light, cool spot. A warm living room causes leaf drop and pests.

Harvest

Pick lemons when they are yellow and give slightly. They can also stay on the tree for some time.

Tip: Keep it outdoors in the sun from May to October and overwinter it light and cool at 5–12 °C. Use soft water or rainwater and give citrus feed regularly in summer.

Lemon: when to prune it?

Pruning months: March.

When: In March, before it starts growing and goes outside. You can also remove rootstock shoots at any time.

How:

• Cut out dead, weak and crossing branches.
• Shorten over-long branches to just above a leaf, to get a neat, compact crown.
• Remove shoots from below the graft union straight away: they come from the rootstock and do not give good fruit.
• Shorten or remove long, bare water shoots to keep the crown balanced.

Caution: Wear gloves: many lemon trees have sharp thorns.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Semi-ripe cuttings

In July–August, take 10–15 cm cuttings, remove the lower leaves and insert them in moist cutting compost under plastic at 20–25 °C. Roots form within a few weeks.

Seed

Pips from a lemon germinate easily at 20–25 °C and make an attractive green plant. It only flowers after many years and the fruit is unpredictable.

Lemon: how does it get through the winter?

Hardy to −3 °C: protect in harsh winters.

• Not hardy: it tolerates at most a brief, light frost of −3 °C. Bring it in in October, before the first night frost.
• Overwinter it light and cool at 5–12 °C, for example in a cool greenhouse, a conservatory or a bright, unheated room.
• In winter, water much less and give no or very little feed.
• In spring, let it get used to the outdoors gradually, in the shade at first, or the leaves will scorch.

Diseases and pests

• Yellow leaves: Yellow leaves with green veins from hard water or lack of feed; wholly yellow leaves from overwatering. Use rainwater, citrus feed and a free-draining pot.
• Leaf drop in winter: Too warm and too dark, or a sudden change of position. Move it somewhere cooler and lighter and water less.
• Scale insects and mealybugs: Brown bumps or white fluff and sticky leaves with black sooty mould. Wipe off with a soft brush and soapy water.
• Red spider mite: Speckled, dull leaves with fine webbing, in warm, dry indoor air. Spray the leaves with water and move the plant somewhere cooler.
• Fruit drop: Some of the young fruits always drop: that is normal. If many fall, check for drought or waterlogging.

Through the year

• January: Cool and light indoors. Little water. Check for pests.
• February: Check for pests. Fragrant flower buds.
• March: Prune. Flowering begins.
• April: Repot. Start citrus feed.
• May: After mid-May, move outside gradually. In flower.
• June: In flower. Feed every one to two weeks.
• July: In hot weather, check daily whether it needs water. Take cuttings.
• August: Feed. Take cuttings.
• September: Last feed.
• October: Bring in before the first frost.
• November: Harvest ripe lemons. Less water.
• December: Cool and light indoors. Harvest.

Edible and useful

Fruit (December–April)

A potted lemon tree flowers mainly in spring; the fruits take 6 to 9 months and turn yellow in winter, from December to April. Pick them when they are fully yellow and give slightly; they can stay on the tree for weeks. Use both juice and zest, only from unsprayed fruit: in lemonade, lemon curd, preserved lemons, limoncello and wherever a fresh touch is welcome. The flowers are edible too and wonderfully fragrant.

Storing

Lemons keep for a few weeks somewhere cool or in the fridge. Grate the zest and squeeze the juice, and freeze them separately (in an ice-cube tray). Preserved in salt, they keep for a year.

Fermenting

Lemons in salt (as in Morocco) ferment for a month: the peel becomes soft, salty and sour and gives tagines, stews, salads and dressings a deep lemon flavour.

Caution: Only use the zest of lemons that have not been sprayed. Garden-centre plants are often treated with products not approved for food: only eat fruit from a newly bought plant after a year, once new fruits have grown at home. The tree barely tolerates frost: overwinter it somewhere cool and light (5 to 12 °C).

Eating and using is at your own risk: see the terms of use.

Recipes

• Salt-preserved lemons (Fermentation · 1 litre jar · 20 min + 1 month)
• Limoncello (Liqueur · ± 1 litre · 30 min + 2 weeks)

Did you know?

• The lemon is not a wild species but an ancient hybrid whose parents are the citron and the bitter orange.
• A lemon tree often carries buds, flowers, green fruits and ripe fruits all at the same time.
• The word orangery recalls the citrus trees that wealthy families once overwintered in these glass buildings.