Tree · Rutaceae
Lemon
Citrus limon
Give it full sun, deep but infrequent water, and frost protection, and a lemon tree keeps pumping out fruit for decades.
Full sun
Every 7–14 days
USDA 9–11
6–20 ft · 1.8–6 m
Overview
The lemon is a small evergreen tree in the citrus family, and it is a joy to grow, hung with glossy leaves, fragrant white blossom, and tart yellow fruit. It travelled out of Asia through the Mediterranean and thrives wherever winters stay mild, in zones 9 to 11. Plant one in a warm, sunny spot and it fires off flowers and fruit at the same time, sometimes all year long.
Drop a lemon into open ground in frost-free country, or run it in a big pot you can roll under cover the moment cold threatens. A mature tree shoots up to 6 to 20 feet (1.8 to 6 m) tall, while dwarf types stay compact and slot neatly onto a patio or into a sunroom. Nearly every tree you buy rides on a grafted, hardy rootstock, which is exactly why a lemon grown from a pip rarely matches its parent.
Give a lemon what it craves and it pays you back with barely any fuss. Keep frost, soggy roots, and a short list of citrus pests and diseases on your radar. Dial in the drainage and the watering rhythm, keep an eye on that eager new growth, and the tree cranks out fruit for years.
Care
The short version: load it up with full sun and shelter from frost, water deeply only once the top few centimetres of soil dry out, plant it in well-drained soil rich in organic matter, and hit it with a monthly citrus feed through the growing season.
Light
Lemons chase full sun, ideally 8 hours or more a day, and that is exactly what fuels heavy flowering and fruit. They will get by on partial sun or bright indirect light indoors, but drop the light and you land a leggier tree with a thinner crop.
Water
Soak the tree deeply, then hold off until the top few centimetres of soil dry out before the next drink, usually every 7 to 14 days. Citrus balk at both drought and soggy roots, so nail the rhythm rather than the volume. A potted tree dries out faster, so check it more often when the heat climbs.
Soil
Plant into well-drained sandy loam loaded with organic matter, and never let the roots sit in water. A slightly acidic pH of 5.5 to 6.5 keeps the tree feeding itself smoothly. Get the drainage right, because a lemon will not forgive standing water.
Temperature
Lemons love warmth and cruise across roughly 28°F to 100°F (-2°C to 38°C), though frost near that low end nips the tender growth. Hold a potted tree above freezing through winter and it powers straight through.
Humidity
Average humidity of 30% to 60% suits a lemon fine, so there is nothing to sweat here. Indoors, keep an eye on the dry air near a heater, where an occasional misting or a pebble tray does the trick.
Feeding
Feed monthly right through the growing season, spring into late summer, with a citrus-specific fertilizer higher in nitrogen. The extra iron, zinc, and manganese head off the yellowing citrus are prone to.
Pruning
Lemons barely need shaping. Prune lightly in late winter or early spring to clear out dead, crossing, or weak wood and any suckers below the graft union, then thin the canopy just enough to let light and air pour through.
Repotting
Bump a container tree up into a pot one size larger every 2 to 3 years. Roots circling the pot, water running straight through, or growth that stalls despite feeding all shout that it is time to size up.
Size & spacing
A lemon tree climbs 6 to 20 feet (1.8 to 6 m) tall with a spread of 5 to 15 feet (1.5 to 4.5 m), so hand it open room, or grab a dwarf for a tight corner or a container.
When to plant
A lemon runs on warmth and slams to a stop at frost. Get young trees into the ground in spring, once the cold clears out and the soil warms up. Blossom bursts out mostly in spring, and then the fruit takes its time, ripening roughly 6 to 9 months later with peaks that often land in winter.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: spring, after all danger of frost has passed and soil has warmed
- Harvest: Blooms mainly in spring but is everbearing in mild climates; fruit ripens roughly 6 to 9 months after bloom, with peaks often in winter. Trees are typically grafted onto rootstock rather than grown from seed.
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Most lemon trouble lands on the leaves first, whether a pest is mining the new flush or a fungus is blistering the older foliage. Learn to read those early tells and you can pounce before the tree slips. Match what you spot below, then jump on it while your fix still counts.
Streaky mottled leaves, retreating twigs, and unevenly shaped bitter fruit
Blotchy leaves, dying twigs, and lopsided bitter fruit spell out Huanglongbing, or citrus greening, a bacterial disease the Asian citrus psyllid ferries from tree to tree and one that slowly finishes a tree off. No cure exists, so a confirmed tree has to come out to guard the ones nearby. Read the mottling closely, since it sprawls across the veins unevenly and gives itself away against a neat nutrient shortage, then rush any suspect case to your agricultural agency for testing.
Fix:
- There is no cure; remove and dispose of confirmed infected trees to protect the area
- Report suspected cases to your state department of agriculture or extension office
- Manage the Asian citrus psyllid vector
Glossy sticky foliage, sooty smudges, and tiny fixed lumps on branches
Those little fixed bumps clinging to the stems are scale insects, busy drinking sap, and the sticky sheen with black mold is the honeydew trailing behind them. Rub or prune off a light run, then blanket the rest with a narrow-range horticultural oil for full cover. Chase off the ants while you are at it, because they farm the scale and drive away the predators that would happily clean house.
Fix:
- Wipe or prune off light infestations
- Apply horticultural or narrow-range oil for thorough coverage
- Control ants to allow natural predators and parasitoids to work
Oily yellow-brown pustules under aging leaves
Flip a leaf and find greasy yellow-brown blisters underneath and you have run into greasy spot, a fungus that pops up after warm, humid spells and eventually knocks older leaves off the tree. Rake up and bag the fallen leaves where the spores hunker down for winter, then open the canopy with a little pruning so the foliage dries fast. A copper or oil spray timed to the summer flush backs you up where your area recommends it.
Fix:
- Rake and remove fallen leaves that harbor spores
- Improve airflow through pruning
- Apply a copper or horticultural oil spray timed to summer leaf flush where recommended
Shimmering squiggle trails and twisted fresh flush
Spot silvery squiggles snaking through the freshest leaves and you have caught the citrus leafminer, whose larvae burrow inside the soft new flush. Snip off the worst-hit growth and ease up on nitrogen and light pruning, since both keep pushing the tender leaves the pest chases. On a mature tree the marks look dramatic but hardly touch your harvest, so hold back the spray and let the tree power on.
Fix:
- Prune off and dispose of heavily mined new flush
- Avoid excess nitrogen and frequent light pruning that forces vulnerable new flush
- Use horticultural oil on new growth; protect natural parasitoid wasps by avoiding broad-spectrum insecticides
Toxicity
Great news for the cook: the flesh and juice are safe for people. The rest of the tree is another story, since the peel, leaves, and seeds carry essential oils and psoralens the ASPCA flags as toxic to cats and dogs, and the same compounds can upset other animals. Keep rinds, prunings, and any concentrated citrus oils away from your pets and grow on with confidence.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A cat that chews the peel or leaves typically ends up with vomiting, loose stools, drooling, and a flat, sluggish mood. Watch out for concentrated citrus oil on the fur, since it can leave the skin touchy in sunlight.
Dogs Mild
Let a dog gnaw bark, leaves, or peel and an upset stomach, diarrhea, and low energy tend to follow. Strong citrus oils can spark a skin reaction in sunlight too, so keep those products well clear of your dog.
Horses Mild
The oils and psoralens in the peel and leaves can churn a horse's gut and leave it dull. Luckily most horses snub the bitter foliage outright, so real trouble rarely shows up.
Rabbits Caution
A rabbit's delicate digestion clashes with the fragrant oils packed into the peel and leaves. Skip the rind and greenery, and keep even a bit of the juicy flesh to a rare nibble.
Livestock Caution
Cattle, goats, and sheep seldom bother with citrus, but the oily peel and leaves can irritate the stomach if they tuck in. Keep prunings and windfall fruit clear of grazing ground to stay safe.
Birds Caution
Keep the concentrated oils in the rind and leaves away from pet birds, whose systems struggle with those compounds. A small taste of the plain flesh is as far as it should ever go.
People Flesh safe
For people the flesh and juice are kitchen gold, safe to eat and drink all day long. Work with a heap of peel or oil, though, and your skin can turn sun-sensitive, so rinse your hands before you head out into the light.
Keep peels, leaves, seeds, and any concentrated lemon essential oils away from pets, and avoid applying citrus oil products to animals.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Hundreds of lemon selections are out there, but a handful turn up in nearly every garden and grocery aisle. These are the standouts worth knowing by name.
Eureka
Eureka is the everyday grocery lemon, near thornless and cheerfully cropping right through the year where winters stay mild.
Lisbon
Lisbon powers out heavy seasonal flushes on a vigorous, thorny frame and takes both cold and heat in stride better than Eureka.
Meyer
Meyer, a lemon-mandarin cross, delivers sweeter, less sour fruit under a thin orange-tinged rind and shines as a dwarf container tree.
How to propagate
Lemons almost always come from grafting, but you can also strike a cutting or sow a seed if you happily take on the trade-offs each route throws your way.
GraftingDemanding
Active growing season, late spring to summer · A season or more for the graft to take and push growth
Grafting drives the commercial trade, budding a chosen lemon scion onto a vigorous, disease-resistant rootstock right through the active growing season from late spring into summer. It rewards a practiced hand, and the graft needs a season or more to knit together and start pushing growth. Stick with it and you land a tree that fruits true and rides on the rootstock's toughness.
Stem cuttingsModerate
Spring to early summer from semi-hardwood growth · Several weeks to a few months to root
Take semi-hardwood cuttings in spring or early summer and a lemon will strike in anywhere from several weeks to a few months. The tree then grows on its own roots, an easier win than grafting, though it hands back the disease resistance and vigor a solid rootstock would have brought to the table.
SeedModerate
Sow fresh seed from ripe fruit · Many years to reach fruiting size, if ever true to type
Sow fresh seed from a ripe fruit for a fun, easy experiment, but the seedlings sprout variable, often thorny, and take many years to reach fruiting size, if they ever fruit true to the parent at all. That is why seed mostly powers breeding work and rootstock raising rather than a tree you plan to harvest.
Myths
Grocery lemon pips sprout trees every bit as good as the parent.
Shop lemons ride on a separate grafted rootstock chosen for disease resistance and reliable fruit, so a seedling simply cannot copy its parent. Expect a slow, variable, often thorny tree that may never fruit the way you were dreaming of.
Neither the lemon tree nor its oil poses any threat to pets.
The ASPCA lists Citrus limon as toxic to cats and dogs, thanks to the limonene, linalool, and psoralens loaded into the peel, leaves, and seeds. Keep the rind, foliage, and any concentrated citrus oils well out of a pet's reach.