Tree · Rutaceae
Orange
Citrus × sinensis
Give it full sun, warmth, and well-drained soil, and a sweet orange tree rewards a home with fruit for decades.
Full sun
Every 7–14 days
55–100°F · 13–38°C
USDA 9–11
Overview
The sweet orange has earned its place as the most widely grown citrus in the world, an evergreen tree whose white spring blossom perfumes a whole courtyard and whose fruit brightens the cool months. It keeps company with lemons and limes in the rue family, and it settles most gracefully into homes where winters stay mild, roughly USDA zones 9 to 11. Where frost looms, a large pot lets the tree hold court on a sunny terrace and retreat indoors for the season.
An orange tree belongs to the slow, settled rhythm of a home rather than a single season. It grows at a moderate pace toward 20 to 30 feet (6 to 9 m) in open ground, and it lives and bears for decades, becoming a fixture of the garden it anchors. It flowers in spring and carries its fruit through fall and winter, so a single branch often wears blossom and ripening oranges together, a quiet piece of daily theater outside a kitchen window.
Nearly every orange begins as a graft, a chosen variety married to a hardy rootstock that weathers cold and disease, which is simply why a breakfast seed will not repeat the fruit. Chosen to suit the local climate and given sun and steady water, an orange asks little and gives a home the kind of standing presence that shapes a courtyard, frames a doorway, and marks the turning of the year.
Care
The short version: full sun, warmth, and well-drained soil, watered deeply but seldom, with a balanced citrus feed across the growing season, and the tree fits easily into the rhythm of a home.
Light
An orange wants full sun, ideally 8 or more hours a day, which is what sweetens the fruit and suits a bright, south-facing corner of a garden. It tolerates a little afternoon shade, but a sunnier spot rewards the home with a fuller, sweeter crop.
Water
Water deeply but seldom, letting the top half of the soil dry between drinks, which usually falls every 7 to 14 days, an easy rhythm to fold into a weekly routine. Young trees and those in pots drink more, while a settled tree in the ground takes a dry spell in stride. Soggy, waterlogged soil is the one thing an orange will not abide.
Soil
Plant in well-drained sandy loam where water never lingers around the roots. A pH between 6.0 and 7.5 keeps the tree content, and good drainage matters far more than the exact soil type beneath it.
Temperature
Oranges are at ease from about 55°F to 100°F (13°C to 38°C) and want a frost-free spot. A hard freeze harms the wood and fruit, so a tree near the edge of its range earns its keep in a handsome pot that can move indoors when the cold arrives.
Humidity
Average humidity of 50% to 70% keeps an orange comfortable, the very air most warm regions offer on their own. A tree brought indoors for winter welcomes a touch more moisture in dry, heated rooms.
Feeding
Feed with a balanced citrus fertilizer carrying micronutrients such as iron, zinc, and manganese. Apply it across the growing season, from spring into late summer, then ease off as the weather cools and the garden quiets.
Pruning
An orange asks for little pruning, which keeps its upkeep gentle. Take out dead, damaged, or crossing wood and remove any suckers below the graft, working in late winter or early spring before the new flush.
Repotting
A container tree welcomes a fresh, larger pot every 2 to 3 years. Roots circling the pot, water running straight through, or growth slowing with yellow leaves are the signs it is ready to move up and keep its place on the terrace.
Size & spacing
A standard orange tree reaches 20 to 30 feet (6 to 9 m) tall and spreads 12 to 20 feet (3.6 to 6 m) across, so give it open room away from buildings and other trees, where it can anchor a garden as a lasting feature.
When to plant
An orange tree wants warmth and will not sit through a hard frost, so its calendar follows the last freeze. A new tree set out in spring, once that freeze has passed, blooms the following spring, with fruit ripening from fall through winter and into spring depending on the variety, a slow procession that gives a garden something to look forward to.
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 trouble on an orange tree announces itself first on the new leaves and the fruit, the parts a passing eye notices soonest. A couple of these are insects a gardener can manage, while two are serious diseases worth catching early. Find the match below, then act before it moves through the rest of the tree.
Mottled yellow leaves beside small, lopsided fruit
When the leaves go blotchy and the fruit turns small, lopsided, and bitter, the culprit is citrus greening, or huanglongbing, the most serious ailment a citrus tree can face. The Asian citrus psyllid, a tiny insect, carries the bacterium from tree to tree, and once a tree is infected nothing brings it back. The responsible course is to remove and destroy the tree for the sake of the ones around it, and to let the local agricultural office know.
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
Corky tan lesions ringed in yellow on fruit and leaves
Raised, scabby lesions ringed in yellow are the signature of citrus canker, a bacterial disease that travels on wind-driven rain and on wet hands. The affected wood and fruit should be removed and destroyed, and a copper spray helps where the rules allow it. Because many regions treat canker as reportable, it is wise to check the local quarantine before moving anything at all.
Fix:
- Remove and destroy affected plant material
- Apply copper-based sprays where permitted
- Follow local quarantine and reporting requirements
Sticky leaves, sooty film, and bumps along the stems
The small bumps that stay put along the stems are scale insects, and the tacky sheen and black film beneath them is the honeydew they leave. Horticultural oil clears them, and any twig gone crusty is best trimmed away. It pays to notice the ants as well, since they tend the scale and see off the natural predators that would otherwise keep the tree in balance.
Fix:
- Apply horticultural oil to smother scale
- Prune heavily infested twigs
- Conserve natural predators and parasites
Silver winding trails across curled new leaves
Those silvery, wandering trails across the fresh leaves are the mark of the citrus leafminer, whose larvae feed inside the soft new growth. A mature tree carries the blemish with ease and simply grows past it, so it asks nothing of you. On a young tree it is worth easing back on the tender growth that invites the moth, with horticultural oil held in reserve for a heavier season.
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 the flesh of an orange is a safe, everyday pleasure, yet the tree asks for a little care in a home shared with animals. Its peel, leaves, and seeds hold essential oils and psoralens that upset a pet's stomach and can leave the skin touchy in sunlight. Keep peels and prunings clear of cats, dogs, horses, and other animals, and offer only a little flesh as a rare treat.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
The oils in the peel and leaves tend to bring on drooling, vomiting, and a spell of diarrhea in a cat. A larger helping can leave it dull and low, and the psoralens make its skin sensitive in bright sun.
Dogs Mild
A dog that works over the peel or leaves usually ends up with an unsettled stomach, vomiting, and loose stools. A bigger amount drains its energy, so its own treats make the far kinder choice.
Horses Mild
The oils and psoralens in the foliage and rind can disturb a horse's digestion and take the edge off its mood. Keeping prunings and peels out of the paddock spares a curious horse the temptation.
Rabbits Mild
The essential oils in citrus leaves and peel overwhelm a rabbit's delicate digestion and can leave it uninterested in food with soft stools. A tiny sliver of flesh, only now and then, is as far as it should ever go.
Livestock Mild
Goats, sheep, and cattle may sample fallen leaves or peel and come away with a mild stomach upset. Clearing citrus trimmings from grazing areas keeps the animals from making a meal of them.
Birds Caution
The oils gathered in the peel and leaves are best withheld from pet birds, even as a small taste of the flesh sits fine. A little seedless flesh is plenty, with the rind left aside.
People Flesh safe
The juicy flesh is a wholesome, everyday food with nothing to worry about. The peel, leaves, and seeds are best kept out of the bowl, as 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 exist, sorted for the most part into the ones grown to eat and the ones grown to juice. The few gathered here are the names a home grower is most likely to plant or recognize.
Valencia
A late-season juicing orange gathered from spring into summer, prized for its almost seedless fruit and its exceptional juice.
Washington Navel
The seedless eating orange recognized by the small second fruit, the navel, set into its blossom end.
Hamlin
An early, cold-hardy juice orange planted throughout the groves of Florida.
Blood orange (Moro)
Its flesh deepens to a rich red once cool nights draw out the anthocyanin pigment.
How to propagate
Oranges are nearly always grafted, which secures both the fruit and a hardy root, though a tree can be grown from seed by anyone with a few years to give it.
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 established route to an orange tree, chosen alike in commercial groves and home gardens. The work is done in spring or early summer, while the bark slips freely, and the union settles over a few months. It delivers fruit true to the parent along with the cold and disease tolerance of the rootstock, though the young tree still asks for 3 to 5 years before it begins to bear.
SeedEasy
Sow fresh seed in spring · Germinates in a few weeks but can take many years to fruit
Raising an orange from seed is simple, provided patience is part of the plan. A fresh seed sown in spring sprouts within a few weeks, yet the tree can take many years to fruit and often will not come true to the parent. For that reason seed is chiefly a means of raising rootstock or of quiet experiment.
Myths
Oranges are completely safe for cats and dogs because the fruit is edible for people.
It is a natural assumption, yet the ASPCA lists orange as toxic to cats and dogs, since the peel, leaves, and seeds carry essential oils and psoralens that unsettle the stomach. The juicy flesh is a good deal gentler, though even that belongs to the category of small, occasional treat for a pet.
A seed from a store-bought orange grows a tree just like its parent that fruits in a year or two.
It is a tempting idea, but sweet oranges are nearly always grafted onto a rootstock rather than raised from seed. A seedling can take many years to bear and often will not resemble the parent, which is why a seed-grown tree tends to serve as rootstock or as a pleasant experiment.