Tree · Rutaceae
Blood Orange
Citrus × sinensis
Give it full sun and cold winter nights, and your blood orange will ripen flesh the color of garnet.
Full sun
Every 7–14 days
USDA 9–11
8–30 ft · 2.4–9.1 m
Overview
The blood orange is a sweet orange that hides a lovely surprise inside. Slice one open and the flesh shifts from streaked orange to deep garnet, all thanks to anthocyanins, the same gentle pigments that color berries. It is part of the citrus family and grows as an evergreen tree, sweetly scented in bloom and laden with fruit through the cooler months, so there is plenty to look forward to.
The most charming part is how that color comes to be. The flesh only deepens to red when warm days are followed by cold winter nights, so the very same tree raised in a mild, steady climate will give you paler fruit instead. That little quirk is what ties the finest blood oranges to places like Sicily, where the chill rolling off Mount Etna enriches the color season after season.
Happily, a blood orange asks for nothing more than any sweet orange would. Give it full sun, free-draining soil, and shelter from hard frost, and it will repay your patience far more than your fussing. A grafted tree needs a few years to settle, but once it feels at home it can keep fruiting for decades, so any early stumble is easy to forgive.
Care
The short version: full sun, soil that drains freely, and watering that stays steady yet careful so the roots never sit waterlogged. Feed through the growing season, tuck the tree away from frost, and let those cold winter nights do the quiet work of coloring your fruit.
Light
Your blood orange loves full sun, and the more it gets the better, since sunshine feeds both the crop and the sweetness of the fruit. It will tolerate a touch of partial shade if it must, but in too much shade it flowers less and sets fewer oranges, so a bright spot really pays off.
Water
Give young trees a good soak twice a week for the first month, then gently ease back as the roots spread out and grow more self-reliant. An older tree mostly needs help only during dry spells, and the single thing to steer clear of is waterlogging, which citrus roots simply cannot cope with.
Soil
Settle the tree into well-drained loam, silt, or sandy soil where water never gathers and sits. A slightly acidic pH of 5.5 to 6.5 suits it nicely, though good sharp drainage matters far more than hitting that number on the nose, so do not fret over it.
Temperature
This tree copes with a generous range, from about 41°F to 100°F (5°C to 38°C), though a hard freeze will harm the leaves and twigs. Cold nights are actually welcome when the fruit is ripening, since they are exactly what coax the flesh to turn red.
Humidity
Ordinary humidity of 40% to 60% keeps your tree content, so most climates within its range will suit it without any trouble. Steady airflow around the branches counts for more than chasing any precise number, so do not lose sleep over a humidity gauge.
Feeding
Offer a balanced citrus fertilizer such as 8-8-8 with micronutrients across the growing season, roughly February to October. Spreading those feedings through spring and into fall keeps the growth gentle and steady rather than pushing it too hard, which the tree appreciates.
Pruning
Blood oranges need very little pruning, which is one less thing to worry about. Trim away dead, damaged, or crossing branches and clear any suckers below the graft union, and do it once the fruit has ripened, since the flowers form on new wood.
Repotting
A potted tree will want a roomier home every 2 to 3 years or so. Roots circling the inside of the pot, roots creeping out of the drainage holes, or growth that has quietly stalled are all friendly signals that it is time to move it up a size.
Size & spacing
Planted in the open ground a blood orange can grow 8 to 30 feet (2.4 to 9 m) tall with a canopy reaching 8 to 15 feet (2.4 to 4.5 m) across. Give it that much open space and the branches will catch full sun while air flows freely through the tree, which keeps it healthy and happy.
When to plant
Blood oranges keep a winter rhythm, and it is an easy one to follow. Set young trees out in spring once frost has passed, enjoy the fragrant white flowers that arrive a little later, and then gather the ripe fruit from winter into early spring, after a stretch of cold nights has turned the flesh red.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring, after danger of frost has passed
- Harvest: Fragrant white flowers in spring; blood oranges ripen winter to early spring (about December to April), developing deepest flesh color after cool nights
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Most blood orange worries come down to insects, cold, or a single serious disease, and the good news is that early action gives you a real chance to save the tree or at least slow things down. Look through the signs below, find the one that matches yours, and step in before any trouble has a chance to spread.
Patchy yellow leaves with small, lopsided fruit
Take a breath, because this one is serious: those uneven yellow leaves and crooked, bitter fruit point to citrus greening, the disease also known as Huanglongbing. A little bug called the Asian citrus psyllid spreads it from tree to tree, and sadly no remedy can bring an infected tree back. The kindest thing you can do is pull and destroy the sick tree, start fresh with certified disease-free stock, and keep that psyllid away before it ever finds your garden.
Fix:
- Remove and destroy infected trees
- Control the Asian citrus psyllid vector
- Plant certified disease-free stock
Falling leaves and dying twig tips after the cold
This is simply freeze damage, and it looks more frightening than it usually is. A hard frost leaves the foliage water-soaked, then brown, so the leaves drop and the twig tips wither. Wrap the tree on freezing nights, settle it in the warmest corner you have, and hold off on cutting anything until spring growth appears, because those bare twigs so often surprise you with fresh leaves once the warmth returns.
Fix:
- Provide cold protection during freezes
- Prune out dead wood only after new growth resumes in spring
A dark, dusty film over the leaves and fruit
Try not to worry when you spot this dark layer, because it is only sooty mold, a harmless fungus that settles on the sticky honeydew dropped by aphids, whiteflies, scale, or mealybugs. The mold itself barely touches the tree and wipes away with ease, yet it is a gentle hint that tiny sap-suckers are at work below. Treat those insects with horticultural oil and rinse the leaves clean, and the mold simply loses its food and fades.
Fix:
- Control the honeydew-producing insects with horticultural oil
- Rinse foliage to remove mold
Toxicity
The juicy flesh is a treat for people, but the rest of the tree is best kept away from animals. Its peel, leaves, and seeds carry essential oils and psoralens that can unsettle a pet's stomach and irritate skin. With a little care, keep cats, dogs, horses, and grazing animals clear of the rind, the foliage, and any prunings.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A curious cat that nibbles the peel or leaves might drool, be sick, or pass loose stools and seem a bit flat for a while. The oils in the rind can leave the skin looking red and itchy too, so a quick rinse helps.
Dogs Mild
A dog that gets into the rind or foliage may end up with an upset tummy, some vomiting, or diarrhea, and the oils can leave the skin irritated where they touch. None of it is usually lasting, but it is no fun for either of you.
Horses Mild
The ASPCA flags sweet orange as toxic to horses, since the very same peel oils and psoralens unsettle the gut. To be safe and kind, keep prunings and windfall peels well clear of the paddock.
Rabbits Caution
The peel and leaves hold those same irritating oils, so they make a poor snack for a rabbit. A little piece of the flesh now and then is fine, but it is best to set the rind and foliage aside.
Livestock Caution
Goats, sheep, and cattle can manage a small taste of pulp, but a belly full of bitter peel and leaves leaves them with digestive trouble. Keeping them away from the tree and its trimmings spares everyone the bother.
Birds Caution
Many birds happily peck at a little of the juicy flesh as a treat, yet the oily peel and pith are kindest left out of reach.
People Flesh safe
Good news for the cook: the juicy flesh is perfectly safe to eat and a real pleasure. Handling lots of peel can make sensitive skin tingle in sunlight, thanks to the psoralens in the oil, so wash your hands and enjoy.
The fleshy fruit pulp is edible, but keep peels, leaves, seeds, and concentrated peel oils away from pets.
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
Three blood orange cultivars come up time and again, and each brings its own mix of color, sweetness, and season. These are the friendly few worth getting to know by name.
Moro
Of the three, Moro rewards you with the deepest and most dependable color, a crimson-to-burgundy flesh that holds the highest anthocyanin content and carries a berry note close to raspberry.
Tarocco
If you want sweet and forgiving, Tarocco is Italy's most widely grown blood orange, low in acid with hardly a seed and flesh that shades from orange to red.
Sanguinello
Sanguinello is a late-season Spanish cultivar with few seeds and a gentle red blush that stays good on the tree long after it has ripened, so there is no rush to pick.
How to propagate
Blood oranges are raised almost entirely by grafting, a method that copies a beloved tree down to the last detail. Growing from seed is possible if you are feeling adventurous, but it does ask for years of patience and makes no promises.
GraftingDemanding
Spring to summer when the bark slips · 1 to 2 years to a sellable tree; about 3 to 5 years to fruiting
Nearly every blood orange you will ever buy started as a graft, and there is real comfort in that, because it copies a good tree exactly. You join a bud of your chosen cultivar onto a rootstock in spring or summer while the bark still slips, which keeps the fruit true and lends the tree the rootstock's hardiness against cold and disease. It does take a steady hand, and you should plan on 1 to 2 years to a tree worth selling and 3 to 5 years before it fruits.
SeedModerate
Spring · Several years; many seedlings come true due to nucellar embryony but are slow to fruit
If you simply want to play, sowing a seed in spring is easy and well worth a try. Thanks to a quirk called nucellar embryony, many citrus seeds come true to the parent, yet the young plants throw thorny juvenile growth and need several years to fruit. Just go in expecting a slow, surprising tree rather than a quick twin of the one you started with, and enjoy the journey.
Myths
Blood oranges are a man-made cross or a genetically modified fruit.
You can relax on this one. The red comes from anthocyanins, the very pigments that color berries and red cabbage in nature. A blood orange is simply a pigmented version of the everyday sweet orange, Citrus x sinensis, that came about on its own with no lab and no crossbreeding involved.
Blood oranges need a hot tropical climate to turn red.
It is almost the reverse. The flesh only reddens when warm days meet cold nights, which is why the richest color comes from regions with chilly winters, such as the slopes near Mount Etna in Sicily, and not from constant tropical heat.