Overview
What a lemon tree needs, when it fruits, and whether it suits your home.
A lemon tree in a pot flowers and fruits at the same time, and the scent of its blossom fills a room. It is particular about a few things: a sunny patio in summer, a bright, cool room in winter, compost that drains fast, and a regular citrus feed. Winter overwatering is one of the commonest problems.
Quick facts
- Botanical name
- Citrus limon
- Soil pH
- 5.5 – 6.5
- Feeding
- Heavy feeder
- Temperature
- 13 – 29 °C
- Hardiness
- USDA zone 9b and warmer
- Height
- Up to 150 cm (59 in)
- Propagation
- Cutting, Grafting
Optimal growth
Survives −2 °C
Growing details
- Frost sensitivity
- Frost tender
Growing calendar
- Repot: March, April
- Plant out: May, June
- Flowering: January, February, March, April, May, June, July, August, September, October, November, December
- Harvest: January, February, March, April, May, October, November, December
In spring, when roots show through the drainage holes. In a cool climate: pots go outside once nights stay above 10 °C (50 °F), after hardening off. Lemons flower on and off through the year, most in late winter and spring (UW-Madison, RHS). Some fruit most of the year; the main crop in autumn to spring, depending on variety (UC, UF/IFAS).
Is this plant right for you?
- Best in a pot
- Frost tender
- Winter indoors
- Fragrant blossom
- Self-fertile
- Heavy feeder
- Toxic to pets
Toxic to pets
Leaves, skins and plant material are toxic to dogs, cats and horses; the fruit flesh is edible (ASPCA).
Before You Grow
Choose a grafted tree of a compact lemon, and plan a sunny summer spot and a bright winter one.
Buy a grafted tree that is already flowering or fruiting: seedlings can take ten years to crop.
What you need
A grafted tree
Already flowering or fruiting. See choose your lemon.
A pot with drainage holes
Stepping up gradually; the final pot is 46 to 91 cm (18 to 36 in) across (Clemson). See potting.
Citrus compost
Or a gritty, fast-draining mix. See compost.
Summer and winter citrus feed
Lemons are hungry all year. See feeding.
A bright, cool winter spot
A conservatory, porch or sunny window. See winter indoors.
A plant dolly
For moving a heavy pot in and out (Clemson).
Choose your lemon
Lemons are the RHS’s first suggestion for newcomers to citrus: they need less heat to ripen than oranges, and flower on and off all year (RHS, UW-Madison).
Meyer lemon (Citrus × meyeri), a cross of lemon and orange, has rounder, orange-yellow, sweeter fruit and is compact and hardier than other lemons, to about -6 °C (22 °F) (Penn State). It is often recommended for home growers (Clemson). ‘Improved Meyer’ resists a virus that once affected the variety (UF/IFAS).
Eureka is the true lemon of the shops, sharper and larger; the RHS lists ‘Garey’s Eureka’.
Grafted, not seed-grown. Most citrus is sold grafted so it fruits young; lemons need one to three years to mature before flowering (Clemson). Seedlings take far longer; see propagating. Buy a tree already in flower or fruit.
Rootstock. Dwarfing rootstocks keep citrus to 1 to 1.5 m (3 to 5 ft) in pots (UW-Madison).
Lemons and other citrus compared
-
Lemon
- Winter minimum
- About 5 °C (42 °F) for some
- Notes
- Flowers most of the year; the RHS starter citrus
-
Kumquat
- Winter minimum
- 7 °C (45 °F) or more
- Notes
- Small, tart fruit; scented flowers
-
Lime
- Winter minimum
- Above 10 °C (50 °F)
- Notes
- Needs warmth; ‘Bearss’ is thornless
-
Calamondin
- Winter minimum
- At least 13 °C (55 °F)
- Notes
- Ornamental; sour fruit for preserves
Winter minimums from the RHS, for citrus in pots. If your winter spot is cool, a lemon is the safest choice.
Where lemon trees grow best
Citrus need sun and warmth in summer, and bright, cool shelter in winter.
Summer. Outdoors in the sunniest, most sheltered spot you have (UW-Madison); in the UK that may not be until mid-June (RHS). See winter indoors for when to move it. Warm spots near walls and paving help.
Light. At least six hours of direct sun (Penn State, UW-Madison); Clemson aims for eight. In low light the leaves adapt, but the tree is very unlikely to flower or fruit (UW-Madison). Indoors, a south or southwest window, or a grow light.
Temperature. Citrus grow at about 13 to 29 °C (55 to 85 °F) (UW-Madison), and fruit sets best at 18 to 29 °C (65 to 85 °F) (Clemson). In winter, keep indoor trees at about 13 to 18 °C (55 to 65 °F). Most citrus are damaged below about -2 °C (28 °F) for more than a few hours (UC).
Humidity. 30 to 60% is ideal (Clemson): raise it indoors with a pebble tray or a humidifier.
In frost-free climates such as Florida and coastal California, lemons grow in the ground, where many citrus pass 6 m (20 ft) (UW-Madison); cover them on frosty nights.
- Direct sun
- At least six hours
- Winter indoors
- About 13 to 18 °C (55 to 65 °F)
- Damaged below
- About -2 °C (28 °F)
- Humidity
- 30 to 60%
Compost
Citrus in pots need a slightly acidic, free-draining compost that never stays wet: pH 5.5 to 6.5 (Clemson).
Ready-made. Peat-free citrus compost, or loam-based John Innes No 2 or 3 with about 20% sharp sand mixed in (RHS).
Home mix. Clemson uses four parts shredded aged pine bark to one of peat or coir; UW-Madison adds up to a third perlite or pumice to a standard potting mix.
Avoid garden soil and moisture-retentive mixes: they hold too much water.
Planting
Pot up in fast-draining citrus compost, only a little larger than the rootball.
A pot only a little larger than the rootball: too much compost stays wet and rots the roots.
When to buy and pot up
Buying. Specialist suppliers have the widest choice; garden centres stock citrus mainly in summer. Buy healthy, certified stock (UF/IFAS).
Potting up. Many bought trees can stay in their nursery pot for several years (RHS). Move into a bigger pot in spring, when roots show through the drainage holes.
In the ground only in frost-free climates.
- Pot up in spring.
- Only when roots show through the base.
- In the ground only where frost is rare.
How to pot a lemon tree
Small steps up in pot size keep the compost from staying wet.
-
Choose the pot
Only a little larger than the rootball, about 5 cm (2 in) wider (Clemson), with drainage holes. Deep pots balance a top-heavy tree (UW-Madison).
-
Think about weight
The pot must come indoors every autumn. Plastic is lighter than terracotta or stone.
-
Set the level
The top of the root flare at the compost surface, not buried, to prevent crown rot (Clemson).
-
Fill and firm
With citrus compost, disturbing the roots as little as possible.
-
Water thoroughly
Then let the excess drain away.
Repotting and top-dressing
Citrus need a bigger pot only every few years; top-dress in between.
-
Check the roots
When roots appear through the drainage holes, repot in spring (RHS). Published intervals differ: UW-Madison every one to two years, Clemson every three to five.
-
Go up one size
About 5 cm (2 in) wider; an overlarge pot stays wet and invites root rot (UW-Madison).
-
Top-dress in between
In years you don’t repot, remove the top layer of compost and replace it with fresh (RHS).
Care
Watering, feeding, pruning, flowers and fruit, and moving the pot in and out.
In winter indoors, let the surface dry before watering, and never leave the pot standing in water.
Care through the year
Spring
Repot: if roots show
Repot or top-dress; switch to summer feed from late March. See feeding.
Early summer
Harden off: over 1 to 2 weeks
Move outside gradually. See winter indoors.
Summer
Water: check daily · Thin: to about 20 fruits
Water often, feed, thin fruit, trim strong shoots. See watering.
Autumn
Move in: before nights of 5 to 9 °C
Bring indoors gradually; switch to winter feed from November. See winter indoors.
Winter
Water: let the surface dry
Bright, cool, humid; water sparingly. See watering.
Watering lemon trees
Watering is where most potted lemons go wrong. The rootball should never dry out completely, but never stay soggy either.
Summer. Water regularly to keep the compost just moist, ideally with rainwater. Pots dry fast in hot weather: check daily (RHS), and expect to water almost daily in hot, dry spells (Clemson).
Winter indoors. Let the surface partly dry, then water thoroughly with tepid rainwater and let the excess drain. Err on the dry side: overwatering in winter is one of the commonest problems (RHS).
Check first. Feel the top 5 to 7.5 cm (2 to 3 in) of compost before watering (Clemson). Water deeply and less often rather than little and often (UW-Madison).
Never leave the pot standing in water: roots rot.
Humidity. Stand the pot on a tray of gravel with the water level just below the surface, so the compost doesn’t get waterlogged (RHS).
Feeding lemon trees
Citrus are hungry, heavy feeders and benefit from feeding all year (RHS).
UK approach. Summer citrus feed, high in nitrogen, from late March to October; a balanced winter citrus feed from November to mid-March (RHS).
US approach. A fertiliser with at least twice as much nitrogen as phosphorus or potassium (2-1-1), with trace elements such as iron, zinc and manganese (UW-Madison). Frequent watering washes nutrients out of pots, so Clemson uses a slow-release feed such as 12-6-6, applied several times through the season depending on the product’s release rate.
Yellow leaves don’t always mean hunger: in winter, cold, wet roots can’t take up nitrogen, and leaves green up as the soil warms. Find the cause before feeding (UC). See common problems.
Pruning and thinning fruit
Lemons need little pruning. Flowers come at the tips of new side shoots, so heavy pruning gives a bushy plant with little fruit (RHS).
In summer, shorten strong new shoots to keep the head compact and branching, and remove shoots from the main stem below the crown (RHS).
Suckers. Remove any shoot from below the graft union: it is the rootstock (UW-Madison).
Thin the fruit. Potted trees set far more fruit than they can carry. The RHS suggests no more than about 20 fruits on a 1 m (3 ft) tree.
Thorns. Many citrus have sharp thorns.
Flowers and fruit
Lemons are self-fertile: one tree fruits on its own (RHS, Penn State).
Pollination. The RHS finds hand pollination unnecessary. Indoors, with no insects, Penn State brushes inside each open flower with a small, soft paintbrush to help fruit set.
Fruit drop. Young fruits often fall, especially after a move or a change in temperature. Penn State lost dozens before a few held on; it is normal.
Ripening is slow; flowers and fruit at different stages often share the tree. See harvesting.
Winter indoors, summer outdoors
Citrus won’t reliably survive winter outdoors in cold climates, so pots spend winter in a greenhouse, conservatory, porch or bright room (RHS).
Moving in. UW-Madison moves pots in before nights fall to about 5 to 9 °C (the 40s °F); Meyer lemons are the hardiest. Do it gradually: sudden changes make fruit and leaves drop (Penn State).
Winter spot. As bright as possible: a south or southwest window, or grow lights (UW-Madison). Citrus don’t go dormant and still need light. Cool rather than hot: about 13 to 18 °C (55 to 65 °F) (Clemson). The RHS finds long-term houseplant life not ideal: most citrus like a cool winter spell.
Humidity. Heated rooms are dry: use a pebble tray or humidifier.
Moving out. Once nights stay above 10 °C (50 °F), harden off over one to two weeks, from shade into full sun, or leaves scorch (UW-Madison).
Problems
Leaf drop, yellow leaves and scale insects are the usual troubles.
Common lemon tree problems
Match what you see to its likely cause.
Leaves dropping
- Sudden change
- Overwatering
A sudden change of temperature or light, often after moving indoors or out; dry air or cold draughts; or wet roots in winter (RHS, Penn State). Move plants gradually, keep them out of draughts, and water less in winter.
Yellow leaves
- Hunger
- Wet roots
- Cold
Possibly lack of nitrogen, but also common in winter, when cold, wet roots can’t take it up. Check the watering and temperature first; feed only if it persists as the weather warms (UC).
Young fruits falling
- Normal
- Stress
Trees shed excess fruit, more after a move or a sudden change (Penn State). Keep conditions steady.
No flowers or fruit
- Age
- Light
- Pruning
A young or seed-grown tree, too little light, too little feed, or heavy pruning. Grafted trees fruit in one to three years.
Pale, scorched patches on leaves
- Sunburn
Moved from indoors into full sun too quickly. Harden off over one to two weeks.
Common pests
Indoors and under glass, sap-suckers are the main pests. Washing the leaves now and then helps keep them down (UW-Madison). Insecticidal soap and horticultural oil also kill the pests’ natural enemies: use them only as a last resort, and follow the label exactly (UC, Clemson).
Scale insects
Small brown bumps on stems and leaves, with sticky honeydew. Wipe or scrape them off; insecticidal soap or oil only as a last resort.
Glasshouse red spider mite
Mottled, pale leaves; a common pest of citrus (Clemson, UC). Wash the leaves; soap or oil as a last resort.
Common diseases
Root rot
Pythium and Phytophthora rots in poorly drained compost: the most serious disease of potted citrus (Clemson). Use a gritty mix, a pot that isn’t too big, and never let it stand in water.
Sooty mould
Black coating on leaves, growing on honeydew from sap-sucking pests. Control the pests and wipe the leaves.
Citrus greening
A devastating bacterial disease spread by a tiny insect, the Asian citrus psyllid, in parts of the US. Buy certified trees and follow local quarantine rules (Clemson, UF/IFAS).
Harvest & Use
Telling when lemons are ripe, picking, storing and using them.
Harvesting lemons
Lemons ripen slowly: six to twelve months from flower. Meyer lemons ripen mostly in autumn and winter (UF/IFAS).
Ripe or not? Colour isn’t a reliable guide. Wait until the fruit is full size, then taste one now and then and pick when it suits you (UC).
On the tree. Citrus don’t ripen further once picked, so let them finish on the tree (UC).
Cut, don’t pull. Pulling can damage the fruit; cut it with secateurs and a short piece of stalk (RHS).
No hurry. Ripe lemons hang on the tree for weeks, so pick as you need them.
- Taste, don’t judge by colour.
- Cut with secateurs.
- Pick as needed.
Storing and using lemons
Storage. Undamaged lemons keep for several weeks somewhere cool and airy (RHS).
Using them. Juice, zest and whole-fruit preserves. Meyer lemons’ thin, fragrant skin is especially good for zest and cooking.
Propagation
New trees from semi-ripe cuttings; seedlings don’t come true.
Propagating lemon trees
Semi-ripe cuttings give a tree that fruits like its parent (RHS). Take them in spring or summer (UW-Madison, RHS).
Seed gives a tree that won’t match its parent and can take up to ten years to fruit (UW-Madison, RHS). Don’t sow pips from shop-bought fruit: the RHS warns they can carry plant diseases.
Grafting onto rootstock is how nurseries make compact, early-fruiting trees.
More to Explore
Short answers, related guides, and the sources behind this one.
Frequently asked questions
Why is my lemon tree dropping its leaves?
Usually a sudden move or overwatering in winter. See common problems.
How often should I water a lemon tree in a pot?
In summer, keep the compost just moist and check daily; in winter, let the surface dry first. See watering.
Can a lemon tree live outside all year?
Only where frost is rare. Most citrus are damaged below about -2 °C (28 °F); Meyer lemons take about -6 °C (22 °F).
Do I need two lemon trees for fruit?
No: lemons are self-fertile. See flowers and fruit.
How long do lemons take to ripen?
Six to twelve months from the flower. See harvesting.
Why are the leaves on my lemon tree yellow?
Cold, wet roots in winter, or sometimes hunger. Find the cause before feeding. See common problems.
Can I grow a lemon tree from a pip?
Not from shop fruit: the RHS warns of plant diseases. Seedlings don’t come true and may take ten years to fruit. See propagating.
Are lemon trees toxic to pets?
The leaves, skins and plant are toxic to dogs, cats and horses (ASPCA).
Related guides
Sources
- How to grow citrus (opens in a new tab) Royal Horticultural Society
- Lemon (opens in a new tab) ASPCA Animal Poison Control
- Grow your own lemons (opens in a new tab) Penn State Extension
- Container citrus production (opens in a new tab) Clemson Cooperative Extension
- Meyer lemon (opens in a new tab) UF/IFAS Gardening Solutions
- Indoor citrus (opens in a new tab) University of Wisconsin-Madison Extension
- Growing great citrus (opens in a new tab) UC Master Gardeners of Santa Clara County