Tree · Rutaceae
Lime
Citrus × latifolia
Give it generous light, sharp drainage, and a warm, sheltered spot, and the tree rewards a home for years.
Full sun
Every 5–10 days
USDA 9–11
8–20 ft · 2.4–6.1 m
Overview
The Persian lime is the seedless, smooth-skinned market lime prized for its sharp, aromatic juice, and it earns its keep as a living fixture of a warm home. Grown as a rounded small tree of 8 to 20 feet (2.5 to 6 m), it anchors a sunny courtyard or terrace with quiet presence and carries fruit on and off through much of the year in warm climates. Most growers gather the limes while still green, when the acid runs highest.
Think of it as the sun-loving corner of the home garden. It settles into the ground across USDA zones 9 to 11 and slips just as gracefully into a large pot wherever winters bite, so a patio tree can retreat indoors when frost threatens. It stands the cold a touch better than the Mexican (Key) lime, yet a hard freeze still leaves its mark, which is why a sheltered, sunny spot out of biting wind suits it best.
Day to day the lime asks little, and it rewards a routine that keeps it in a bright, well-drained setting. Wet feet bring root and foot rot, an off soil pH locks out nutrients, and a short list of citrus diseases can undo the tree if early signs go unseen. Attend to the drainage and the feeding and the payoff is a long-lived tree that furnishes a space, and a kitchen, for years.
Care
The short version: set the lime in full sun and free-draining sandy loam, water deeply but seldom once the top few centimeters dry, and feed through the growing season with a citrus fertilizer that carries the trace nutrients limes need.
Light
A lime tree wants full sun, ideally 8 hours or more a day, to crop well, so give it the brightest spot the setting offers. It will accept a little partial sun, but shade thins the canopy and trims the harvest.
Water
Water deeply once the top few centimeters of soil dry, then let it drain fully. An established in-ground tree gets by on less, while a patio pot dries fast and may need water every few days in heat. The one thing to avoid is waterlogged roots, which invite foot and root rot.
Soil
Plant in well-drained sandy loam, since standing water is the fastest way to lose a citrus tree. A pH of 6.0 to 7.5 keeps nutrients within reach, and a pH that drifts too high is what brings on the yellow, veiny leaves of micronutrient deficiency.
Temperature
Limes favor warmth, roughly 32°F to 95°F (0°C to 35°C), and grow year-round where the climate stays mild. They are tender to frost, so a cold snap calls for cover, or a move indoors for a potted tree.
Humidity
Average household humidity of 40% to 60% suits a lime, so there is no special target to chase. Airflow through the canopy matters more, since warm, still, humid air is what greasy spot and other fungal diseases feed on.
Feeding
Nourish the tree across its active season, spring through late summer, using a balanced citrus fertilizer carrying magnesium, manganese, zinc, and iron. Limes tend to run low on precisely these trace elements, and a complete citrus feed staves off the telltale yellowing before it appears.
Pruning
Limes need little pruning. Take out dead, damaged, or crossing branches and any suckers below the graft union, and thin lightly after harvest to open the canopy. Wear gloves, because the peel and juice oils plus sun can blister bare skin.
Repotting
Move a container tree into a larger pot every 2 to 3 years in spring. Roots circling the pot or escaping the drainage holes, water that runs straight through, and slowed growth with yellowing leaves all say it is time.
Size & spacing
A mature lime reaches 8 to 20 feet (2.5 to 6 m) tall and about as wide, so allow it real room to spread within the space. In a pot it stays smaller, but it still wants air moving freely around the whole canopy.
When to plant
A lime tree asks for warmth and a season free of frost, so place it outdoors in spring once the soil and air have settled into steady heat. In warm climates it blooms on and off all year, and the main crop runs from summer into winter, with the fruit gathered green for the sharpest juice.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Plant in spring after all danger of frost, once soil and air are reliably warm.
- Harvest: Blooms on and off year-round in warm climates; main harvest summer into winter, with fruit picked while green for highest acidity.
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Most lime trouble announces itself on the leaves, so a habit of glancing over the canopy pays off. Some issues resolve with simple sanitation or feeding, while two of the diseases below are serious enough to report. Read what you see, then act before it spreads to the rest of the tree.
Corky tan blemishes rimmed with yellow on leaf, twig, and fruit skin
When corky, yellow-ringed lesions mar the fruit rind as well as the foliage, the culprit is citrus canker, a bacterium that travels on wind-driven rain and on pruning tools passed from plant to plant. That spread onto the rind is what sets it apart from greasy spot. Bag the infected growth, disinfect tools between cuts, and where canker falls under quarantine, notify your local agricultural authorities.
Fix:
- Remove and bag infected leaves and twigs
- Disinfect pruning tools between cuts
- Apply preventive copper sprays
- Report to local agricultural authorities in regulated/quarantine areas
Off-kilter yellow blotching, twig dieback, and undersized bitter fruit
The most serious visitor a lime can host is citrus greening, also called huanglongbing, a disease that has emptied groves across whole regions. Spread by the Asian citrus psyllid, it reveals itself in a blotchy mottle that runs asymmetrically across the leaf midrib and in small, lopsided fruit. There is no cure, so an infected tree must be removed and destroyed, the psyllid kept in check, and every find reported to agricultural authorities.
Fix:
- There is no cure; remove and destroy infected trees to protect others
- Control Asian citrus psyllid with approved insecticides or oils
- Report finds to agricultural authorities
Yellow blotches above and greasy brown blisters beneath the leaves
A canopy that keeps dropping leaves loses the very lushness that made it a centerpiece, and the cause is often greasy spot, a fungus that settles in through warm, humid spells and lingers on the litter rotting below. The heaviest fall comes in late summer and autumn. Clear away the fallen leaves, thin the canopy so light and air move through, and time a copper or oil spray for early summer to keep the tree looking its best.
Fix:
- Rake up and destroy fallen leaves to cut inoculum
- Apply a copper fungicide or horticultural oil in early to mid summer per label
- Prune to improve air circulation
Pale leaves veined in green across the freshest growth
A canopy that pales while its veins stay green, starting with the youngest leaves, is showing a micronutrient shortage of iron, manganese, or zinc, usually because the soil pH sits too high or the roots have stayed wet. A uniform yellowing of the older leaves tells a different, nitrogen-related story. Restore the deep green with a chelated micronutrient spray, a citrus fertilizer that carries those trace elements, and better drainage.
Fix:
- Apply a chelated micronutrient foliar spray
- Switch to a citrus fertilizer that includes micronutrients
- Correct drainage and avoid overwatering
Toxicity
The juice and flesh are safe to enjoy, but the rest of the tree calls for a little care. The peel, leaves, and seeds hold essential oils and psoralens that upset a pet's stomach and can blister human skin in sunlight. Keep prunings, peels, and seeds away from animals, and wear gloves when you tend the tree.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A cat that chews the peel, leaves, or seeds tends toward vomiting, loose stools, and a dull, low mood, with the oils sometimes leaving the mouth or skin irritated as well.
Dogs Mild
For a dog, gnawing on peel, leaves, or seeds usually means an upset stomach and a spell of diarrhea, often accompanied by a flat, depressed air until it passes.
Horses Mild
A horse meets the same peel and leaf oils that bother pets and may go off its feed and turn queasy, so keep prunings and dropped fruit well clear of the paddock.
Rabbits Caution
The aromatic oils in peel and foliage do not agree with a rabbit's sensitive gut, and with nothing to gain from the gamble, lime is best left off the menu entirely.
Livestock Caution
Goats and other stock may take a fallen fruit without harm, yet a belly of bitter peel and leaves can sour the stomach, so fence them away from prunings and windfalls to be safe.
Birds Caution
A taste of the flesh is generally tolerated, though the strong oils in peel and leaves can irritate a small bird, so offer only a little clean fruit and keep the rind out of reach.
People Fruit safe
The juice and flesh are a kitchen staple and perfectly safe to eat. The one caveat is the skin, where peel oils and juice under sunlight can raise a blistering 'margarita burn,' so rinse your hands after handling.
Wear gloves when pruning or zesting; lime juice or peel oils on skin exposed to sunlight can trigger phytophotodermatitis ('margarita burn'), a painful blistering rash.
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
Persian lime answers to more than one name, and a couple of forms appear at nurseries. Here is what those labels really mean.
Bearss
Bearss is the standard Persian lime grown across the US and above all in Florida, a nearly thornless, seedless tree whose smooth-skinned fruit ripens from green to yellow.
Tahiti
Tahiti is simply a second name for the same triploid seedless lime as Bearss, a vigorous tree that weathers cold better than the Mexican (Key) lime.
Companions
A lime grows best beside flowers that pull in the predators of its pests, and worst with grass crowding the trunk where rot likes to start.
Plant near
Sweet alyssum: Its tiny flowers attract hoverflies and parasitic wasps that help control aphids and psyllids.
Marigold: Draws beneficial insects and may deter some pests around young trees.
Keep apart
Turf grass grown up to the trunk: Lawn competes for water and nutrients and holds moisture against the trunk, raising foot-rot risk; keep a mulched, grass-free zone.
How to propagate
Propagating a lime comes down to two routes: the grafting that nurseries favor, or the more patient methods suited to a home garden, and only grafting delivers everything a rootstock has to offer.
GraftingDemanding
Spring to early summer when the bark slips · 1 to 3 years to bearing
Grafting is the nursery's chosen route, and with good reason. Budded or grafted onto a disease-resistant, often dwarfing rootstock in spring or early summer while the bark still slips, the young lime gains vigor, cold tolerance, and disease resistance before it comes into bearing in 1 to 3 years.
Air layeringModerate
Warm growing season · Several months to root, then 1 to 2 years to establish
Air-layering is the more patient home route, worked through the warm growing season, taking several months to root and then 1 to 2 years to establish. The compromise is that an own-rooted tree forgoes the rootstock and ends up more cold-tender and more prone to disease.
Stem cuttingsModerate
Semi-hardwood cuttings in late spring or summer · 1 to 2 years
Semi-hardwood cuttings taken in late spring or summer will root and reach a usable size across roughly 1 to 2 years. As with air-layered trees, these own-root plants forgo the cold hardiness and disease protection a rootstock would confer.
Myths
Limes are just unripe lemons.
Limes and lemons are separate citrus, and Persian lime stands on its own as the hybrid Citrus x latifolia. Growers pick limes green for their sharp acidity, but the fruit turns yellow when fully ripe, which is nothing like an unripe lemon.
A seed scooped from the fruit will raise an authentic Persian lime tree.
Persian lime is a seedless triploid that almost never sets a viable seed, which is why nurseries turn to grafting. Any stray seedling you did manage to sprout would not come true to the parent tree.
Every part of the citrus tree poses a grave poisoning risk to cats and dogs.
The fruit flesh amounts to no more than a mild stomach upset. It is the essential oils and psoralens packed into the peel, leaves, and seeds that the ASPCA flags as toxic, not the juicy part people eat.