Lime

Lime: how do you recognise it?

Habit

Shrubby small tree, in a pot 1.5–2 m tall and 1–1.5 m wide, with thin, branched, often thorny twigs.

Leaves

Evergreen, oval, 5–8 cm, glossy dark green and aromatic when crushed; the leaf stalk has a narrow wing.

Flowers

Small, white, with five petals and a strong, sweet scent, from March to June; sometimes later in the year too.

Fruit

Round, 3–5 cm, with a thin rind; green, turning yellowish-green to yellow when fully ripe, with plenty of sour, aromatic juice and a few pips.

Thorns

Short, sharp thorns in the leaf axils.

Roots

Fine and shallow; sensitive to wet feet and lime in the water or soil.

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

Why grow it?

• Your own limes for dishes, drinks and desserts, with a strong, fresh aroma.
• Evergreen, glossy foliage: an attractive container plant all year round.
• The white flowers smell wonderful in spring, on the patio or in the conservatory.
• Flowers and fruit often hang on the tree at the same time.
• Stays compact in a pot, so it fits on a patio, a balcony or in a cool conservatory.

Lime: where does it grow best?

• Summer: outdoors from mid-May, in the sunniest, warmest and most sheltered spot on the patio.
• Winter: indoors in a bright, cool place at a minimum of 10 °C, such as a conservatory, a cool porch or in front of a large window.
• Compost: open, slightly acidic citrus compost, or potting compost with some coarse sand or fine grit; never chalky soil.
• A pot with drainage holes and a layer of gravel at the bottom; do not leave water standing in the saucer.
• Sheltered from wind and draughts; do not leave it outdoors too long in autumn.

Light

Sun

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

2 m tall, 1.5 m wide

Hardiness

Frost tender: overwinter indoors (above 2 °C)

Goes well with

• Olive: Another Mediterranean container plant that overwinters in a bright, cool place.
• Bay laurel: Evergreen, for the same sunny corner of the patio.
• Rosemary: Fragrant foliage beside the lime, and a good pairing in the kitchen.
• Lavender: Low, fragrant pots at the foot of the lime.
• Basil: An annual herb in a pot alongside, which also loves warmth.

Lime: when and how to plant it?

Plant in April–May.

1. Repot in April–May, before moving it outdoors, when the roots fill the pot; every two to three years is enough.
2. Choose a pot only 3–5 cm wider than the old one: in an oversized pot the compost stays wet too long.
3. Put a layer of gravel or clay pebbles in the bottom and use citrus compost.
4. Set the tree at the same depth as before; the graft union must stay above the surface.
5. Firm the compost and water until it runs out of the bottom of the pot.
6. For a large tub you no longer repot: replace the top 5 cm of compost with fresh every spring.

Care

Watering

Water only when the top 2–3 cm feel dry, then thoroughly. Rainwater is best: hard tap water causes yellow leaves.

Feeding

Citrus fertiliser every two weeks from April to September; none in winter.

Moving out and in

After mid-May, let it acclimatise for a week in partial shade before it goes into full sun, and bring it in during October before the nights turn cold.

Humidity

Mist the leaves now and then indoors in winter; dry air attracts red spider mite.

Harvesting

Pick the limes when they are green, glossy and juicy and give slightly when squeezed. Left on the tree, they turn yellow and lose some freshness.

In the kitchen

Juice and grated zest in dressings, curries, drinks, ceviche and desserts. Grate only the green outer layer, not the bitter white pith.

Tip: Overwinter it in a bright place at a minimum of 10 °C and water sparingly then: cold, wet roots are the main cause of leaf drop in winter.

Lime: when to prune it?

Pruning months: February–March.

When: In February–March, before new growth starts. Prune lightly: a lime naturally forms an attractive crown.

How:

• Remove dead, diseased and crossing branches.
• Shorten over-long shoots to keep the crown compact and rounded; cut just above a leaf.
• Remove vigorous, upright water shoots growing from the trunk or thick branches.
• Cut off at once any shoots growing from below the graft union: they come from the rootstock.
• Thin a crowded crown so that light and air reach the centre.

Caution: Wear sturdy gloves: the twigs have sharp thorns.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In summer, take semi-ripe cuttings 10–15 cm long, remove the lower leaves and insert them in moist cutting compost under plastic at 20–25 °C. Rooting takes several weeks.

Seed

Fresh pips germinate easily at room temperature, but such a seedling takes many years to fruit.

Lime: how does it get through the winter?

Hardy to 2 °C: protect in harsh winters.

• Not hardy: it cannot take frost and is more sensitive to cold than lemon. Bring it in during October.
• Overwinter in a bright place at a minimum of 10 °C, ideally 10–15 °C, such as a cool conservatory or porch.
• In winter water sparingly and do not feed; let the compost dry out well between waterings.
• In a warm, dark room it drops its leaves: give it as much light as possible, if necessary under a grow light.

Diseases and pests

• Scale insects: Brown bumps on stems and leaf veins, with sticky leaves. Wipe them off with a cloth or a soft brush and a little soapy water.
• Mealybugs: White, woolly tufts in the leaf axils. Dab them with a cotton bud dipped in a little alcohol, or rinse them off.
• Red spider mite: Fine yellow speckling and webbing on the leaves, especially in dry winter air. Mist the leaves and move the plant somewhere cooler.
• Yellow leaves: Yellow leaves with green veins point to iron deficiency caused by lime: use rainwater and citrus fertiliser. Yellow leaves that drop in winter point to too little light or overly wet compost.
• Leaf drop: After a move, a draught or a sudden change in temperature. Leave the plant in peace in a bright spot; it usually regrows.

Through the year

• January: Indoors, bright and cool. Little water. Watch for scale and spider mite.
• February: Formative pruning. Still little water.
• March: Flowering begins. Finish pruning. Gradually water more and start feeding.
• April: Repot if needed. Citrus fertiliser every two weeks.
• May: Move outdoors after mid-May, first for a week in partial shade.
• June: Flowering and fruit set. Water and feed regularly.
• July: Water when the top of the compost is dry. Take cuttings.
• August: Water and feed. Watch for scale insects.
• September: Last feed. Pick green, juicy fruit.
• October: Bring indoors before the nights turn cold. Harvest.
• November: Overwinter bright and cool at a minimum of 10 °C.
• December: Little water, no feeding. Pick ripe fruit.

Edible and useful

Fruit (September–December)

A lime in a pot flowers mainly in spring; the small fruits are ready in autumn and early winter, from September to December. Pick them when they are green and glossy, feel juicy and give a little when squeezed: if you leave them on the tree, they turn yellow and lose their freshness. This small lime (key lime) is sourer and more fragrant than the large lime sold in shops. Use the juice and the grated green zest, only from your own untreated fruit, in dressings, curries, guacamole, drinks and desserts such as key lime pie.

Storing

Limes dry out faster than lemons: keep them in a bag in the fridge, where they keep for one to two weeks. Grate the zest first, then squeeze the juice; freeze them separately, the juice in an ice-cube tray: that way they keep for 6 months.

Caution: Only use the zest of fruit from your own plant that has 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. Lime juice on the skin can cause brown marks or blisters in bright sunlight: wash your hands after squeezing. The lime is not hardy: overwinter it frost-free, light and cool at 10 °C or more, and harvest indoors or in a greenhouse. Watch out for the sharp thorns.

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

Recipes

• Key lime pie (Dish · 8 slices · 45 min + 3 hrs chilling)
• Limeade with mint (Sap · ± 1 litre · 15 min)

Did you know?

• Key lime pie, the famous Florida dessert, is named after this lime, which used to be grown on the Florida Keys.
• Botanically, citrus fruits are berries with a leathery rind, a fruit type called a hesperidium.
• The makrut lime, whose leaves are used in Thai cooking, is a different species: Citrus hystrix.