Tree · Rutaceae
Orange
Citrus × sinensis
Hand it full sun, warmth, and well-drained soil, and a sweet orange tree keeps the fruit coming for decades.
Full sun
Every 7–14 days
55–100°F · 13–38°C
USDA 9–11
Overview
The sweet orange has climbed to the top spot as the most widely grown citrus on earth, an evergreen tree that shows off glossy leaves, fragrant white blossom, and fruit that colors up right through the cool months. It runs with lemons and limes in the rue family, and it hits its stride where winters stay mild, roughly USDA zones 9 to 11. Frost on the horizon? Plant it in a big pot and roll it indoors for winter.
An orange tree signs on for the long haul, and that is half the fun. It climbs at a moderate pace to 20 to 30 feet (6 to 9 m) in the ground, then keeps living and cropping for decades once it digs in. It bursts into bloom in spring and ripens its fruit slowly through fall and winter, so one branch often carries blossom and ripening oranges side by side.
Almost every orange out there kicks off as a graft, a chosen variety fused to a tough rootstock that shrugs off cold and disease, which is exactly why a breakfast seed won't hand you the same fruit. Pick a variety built for your climate, pour on the sun and steady water, and the tree charges ahead and does the rest.
Care
The short version: full sun, warmth, and well-drained soil, watered deeply but not often, plus a balanced citrus feed through the growing season to keep it cranking.
Light
Oranges chase full sun, ideally 8 or more hours a day, and that is what sweetens the fruit. They will put up with a little afternoon shade, but pile on the sun and the crop comes in heavier and sweeter.
Water
Water deeply but not often, letting the top half of the soil dry between drinks, which usually lands every 7 to 14 days. Young and container trees drink harder, while an established in-ground tree shrugs off dry spells. Soggy, waterlogged soil is the one thing an orange flatly refuses to forgive.
Soil
Plant in well-drained sandy loam where water never pools around the roots. A pH between 6.0 and 7.5 keeps the tree cruising, and good drainage counts for far more than nailing the exact soil type.
Temperature
Oranges thrive from about 55°F to 100°F (13°C to 38°C) and want a frost-free spot. A hard freeze bruises the wood and fruit, so a tree near the edge of its range earns its keep in a pot that rolls indoors for the cold.
Humidity
Average humidity of 50% to 70% keeps an orange happy, the kind of air most warm regions serve up on their own. A tree hauled indoors for winter loves a little extra moisture in dry, heated rooms.
Feeding
Feed with a balanced citrus fertilizer loaded with micronutrients like iron, zinc, and manganese. Spread it through the growing season, from spring into late summer, then ease off as the weather cools.
Pruning
Oranges barely ask for any pruning. Clip out dead, damaged, or crossing wood and snap off any suckers below the graft, working in late winter or early spring before the new flush kicks in.
Repotting
A container tree wants a fresh, roomier pot every 2 to 3 years. Roots circling the pot, water blasting straight through, or growth stalling with yellow leaves all shout that it is time to size up.
Size & spacing
A standard orange tree shoots up to 20 to 30 feet (6 to 9 m) tall and spreads 12 to 20 feet (3.6 to 6 m) across, so hand it open room away from buildings and other trees.
When to plant
An orange tree craves warmth and won't stand a hard frost, so let the last freeze set the starting gun. Plant a new tree in spring once that freeze clears out, and it bursts into bloom the following spring, with fruit ripening from fall through winter and into spring depending on the variety.
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
- Harvest: Blooms in spring; fruit ripens fall through winter and into spring depending on cultivar
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Most orange tree trouble tips its hand first on the new leaves and the fruit, so you get an early shot at it. A couple of these are just insects you can knock back, while two are serious diseases worth catching fast. Match what you see below, then move before it spreads through the rest of the tree.
Blotchy yellow leaves with small, lopsided fruit
This is the heartbreaker to know cold: blotchy yellow leaves with small, lopsided, bitter fruit spell citrus greening, or huanglongbing, the toughest disease citrus ever faces. A tiny insect, the Asian citrus psyllid, hauls the bacterium from tree to tree, and once it lands there is simply no cure. Act fast to shield the trees around you, pull and destroy the infected one, and get word to your local agricultural office.
Fix:
- There is no cure; remove and destroy infected trees to reduce spread
- Control Asian citrus psyllid populations
- Report suspected cases to local agricultural authorities
Tan corky scabs haloed in yellow on fruit and twigs
Raised, scabby lesions rimmed in yellow flag citrus canker, a bacterial disease that rides wind-driven rain and wet hands straight onto the tree. Jump on it: strip off and destroy the infected wood and fruit, and reach for a copper spray where the rules allow. Plenty of regions treat canker as reportable, so check the local quarantine before you move a single leaf.
Fix:
- Remove and destroy affected plant material
- Apply copper-based sprays where permitted
- Follow local quarantine and reporting requirements
Gummy leaves, black soot, and hard little stem bumps
Those stubborn little bumps that refuse to budge are scale insects, and the sticky sheen and black soot below them come straight from the honeydew they drip. Hit them with horticultural oil and snip out any twig that has crusted over, and the tree bounces back. Track down the ants too, because they farm the scale and run off the good bugs that would otherwise clean up for you.
Fix:
- Apply horticultural oil to smother scale
- Prune heavily infested twigs
- Conserve natural predators and parasites
Squiggly silver tracks looping over twisted new growth
Those silver squiggles racing across the new leaves are the calling card of the citrus leafminer, whose larvae carve their way through the soft young flush. Great news on a mature tree: it powers right past the damage, so let it ride. On a young tree, dial back the tender growth that pulls the moth in, and grab horticultural oil the moment the mining ramps up.
Fix:
- Tolerate light damage on mature trees, which usually outgrow it
- Avoid excess nitrogen and pruning that stimulate frequent tender flush
- Use horticultural oil on young trees if needed
Toxicity
For people, an orange is a safe, healthy food, but animals play by different rules. The peel, leaves, and seeds carry essential oils and psoralens that upset a pet's stomach and can leave its skin touchy in sunlight. Keep peels and prunings clear of cats, dogs, horses, and the rest, and hand out only a little flesh as a rare treat.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
The essential oils packed into the peel and leaves usually kick off drooling, vomiting, and a run of diarrhea in a cat. Load up on more and it can go dull and listless, and the psoralens can leave its skin touchy out in the sun.
Dogs Mild
A dog that gnaws the peel or leaves lands an upset stomach with vomiting and loose stools. Bigger helpings drain its energy fast, so steer it back to its own treats and keep the citrus out of paw's reach.
Horses Mild
The oils and psoralens in the foliage and rind can churn a horse's gut and flatten its mood. Clear prunings and peels out of the paddock so a curious horse cannot go nibbling on them.
Rabbits Mild
Citrus leaves and peel pack far too much essential oil for a rabbit's delicate digestion and can knock it off its food with soft stools. A tiny scrap of flesh once in a while is the absolute most a rabbit should ever get.
Livestock Mild
Goats, sheep, and cattle may nose into fallen leaves or peel and pick up a mild stomach upset. Sweep citrus trimmings out of grazing areas so the animals cannot pack themselves full of them.
Birds Caution
The oils concentrate hard in the peel and leaves, so keep those away from pet birds, even though a small taste of the flesh sits fine. Serve up just a little seedless flesh and skip the rind.
People Flesh safe
For people the juicy flesh is a healthy everyday food with zero risk. Leave the peel, leaves, and seeds out of the bowl, since their oils can sting the mouth and stomach.
Keep peels, leaves, and seeds away from pets; the fruit flesh in small amounts is likely to cause at most minor stomach upset.
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 orange varieties are out there to explore, split mostly between eating types and juicing types. These few cover the ones you are most likely to grow or spot right away.
Valencia
A late-season juicing star picked from spring into summer, celebrated for its nearly seedless fruit and knockout juice.
Washington Navel
The seedless eating orange you spot in a flash by the little second fruit, the navel, tucked into its blossom end.
Hamlin
An early, cold-hardy juice orange that fills groves right across Florida.
Blood orange (Moro)
Its flesh flushes a deep, dramatic red once cool nights coax out the anthocyanin pigment.
How to propagate
Oranges almost always get grafted to lock in the fruit and a hardy root, but go ahead and grow one from seed if you have a few years to spare for the ride.
GraftingModerate
During active growth in spring to early summer when bark slips easily · Several months to form a union; 3 to 5 years to begin fruiting
Grafting is the classic, rewarding way to launch an orange tree, and it drives both commercial groves and backyard plantings. Tackle it in spring or early summer while the bark slips easily, and the union knits together over a few months. The payoff is fruit that matches the parent plus the cold and disease tolerance of the rootstock, though the young tree still needs 3 to 5 years before it fires up its first crop.
SeedEasy
Sow fresh seed in spring · Germinates in a few weeks but can take many years to fruit
Sprouting an orange from seed is an easy, fun win, as long as patience comes along for the ride. Drop a fresh seed in soil in spring and a green shoot pushes up within a few weeks, but the tree can take many years to fruit and often won't come true to the parent. That is why seed is mostly a way to raise rootstock or just to experiment for the thrill of it.
Myths
People eat oranges all the time, so the fruit has to be totally harmless to cats and dogs.
Tempting logic, but no: the ASPCA lists orange as toxic to cats and dogs, since the peel, leaves, and seeds pack essential oils and psoralens that upset the stomach. The juicy flesh plays much nicer, though even that stays a small, occasional treat for a pet.
Drop a seed from a shop-bought orange into soil and up springs an exact copy of the parent, cropping in a year or two.
It would be a dream, but sweet oranges are almost always grafted onto a rootstock, not raised from seed. A seedling can take many years to bear and often won't match the parent, which is why seed-grown trees mostly become rootstock or a fun side project.