Orange

Tree facts

Scientific name

Citrus sinensis

Origin

Southern China and Southeast Asia

Tree size

20–30 ft if left alone; usually kept at 12–15 ft

Growth rate

Medium

Sun

Full sun, at least 6–8 hours

Soil

Any soil that drains well, including sand. Never waterlogged; plant high where water stands.

Soil pH

6.0–7.5

Pollination

Self-fertile; one tree is enough

Cold hardiness

Leaves are damaged near 26°F; fruit freezes after a few hours at 28°F. Young trees are more tender.

USDA zones

9b–11

Years to first fruit

2–4 for a grafted tree

Season

Oct–Jun

Water

About every 7 days once established, without rain; more in heat, in pots and while young

Feeding

About every 60 days, Feb–Oct

Pruning

Mar–Apr

Taste

Sweet and juicy with a bright tang; blood oranges add a berry note

Nutrition

High in vitamin C, with folate, potassium and fiber in the whole fruit

Is orange safe to eat? Edible and toxic parts

What you can eat

• Segments and juice
• Zest of the peel, for baking and drinks
• Peel, candied or made into marmalade
• Orange blossoms, distilled into orange flower water

Toxic parts and cautions

• Good to know: Citrus juice or peel oil left on the skin in strong sun can cause a burn-like rash that darkens the skin for weeks (phytophotodermatitis). Wash your hands after peeling or squeezing fruit outdoors.
• Good to know: Sweet oranges don't have grapefruit's drug interactions, but sour (Seville) oranges do. If your medicine warns against grapefruit, check with a pharmacist before using sour orange juice or marmalade.

Pets: The peel, leaves and seeds contain essential oils (limonene, linalool) and psoralens that can cause vomiting, drooling and skin irritation in dogs and cats. A bite of the flesh is usually harmless.

How to eat and enjoy orange

• Fresh segments and fresh-squeezed juice
• Salads with fennel, olives or avocado
• Marmalade and candied peel
• Glazes, marinades and Cuban mojo
• Sorbet and cakes

Orange varieties (8)

• Blood · also Blood orange

  Oranges with flesh streaked or flushed deep red, with a raspberry note. Moro, Tarocco and Sanguinelli are the main kinds.

  Origin: Mediterranean (Sicily and Spain) · Taste: Sweet-tart, berry-like · Season: Dec–Mar · Size: Medium

  The red color needs cold nights, so in Florida the flesh is often only lightly streaked.

• Cara Cara · also Cara Cara navel

  A navel orange with pink-red flesh, colored by lycopene, and a low-acid, berry-like sweetness.

  Origin: Venezuela, 1976 · Taste: Very sweet, low acid · Season: Dec–Mar · Size: Medium to large

• Hamlin

  An early, nearly seedless juice orange and one of the main oranges in Florida groves.

  Origin: Florida, 1879 · Taste: Sweet and mild · Season: Oct–Jan · Size: Medium

  Fairly cold-tolerant for an orange, and usually picked before the worst freezes.

• Moro

  The darkest blood orange, often deep burgundy inside, with a bold, slightly bitter edge.

  Origin: Sicily · Taste: Rich, tart, berry-like · Season: Dec–Feb · Size: Medium

  Colors best after cool nights.

• Navel · also Washington Navel, Washington

  A seedless, easy-peeling eating orange with a small second fruit at the blossom end, the navel.

  Origin: Brazil (Bahia), 1800s · Taste: Sweet and rich · Season: Nov–Jan · Size: Large

  Bears less in hot, humid Florida than in California. The juice turns bitter if it sits, so eat it fresh.

• Parson Brown

  An early, seedy Florida juice orange, among the first ripe each fall.

  Origin: Florida, 1860s · Taste: Sweet, mild · Season: Oct–Dec · Size: Medium

• Pineapple

  An old Florida midseason orange named for its fragrance, with rich, sweet juice and plenty of seeds.

  Origin: Florida, 1870s · Taste: Rich and sweet · Season: Dec–Feb · Size: Medium

  Tends to bear heavily every other year, and the fruit is tender to cold.

• Valencia

  The world's leading juice orange, ripening in spring after the other oranges are done.

  Origin: Probably Portugal; named after Valencia, Spain · Taste: Sweet-tart, very juicy · Season: Mar–Jun · Size: Medium

  Fruit holds on the tree into summer and may turn green again at the stem without losing quality.

Pests and diseases to watch for

• Whiteflies

  Clouds of tiny white flies when a branch is shaken; yellowing leaves and sooty mold.

  What to do: Insecticidal soap or horticultural oil on leaf undersides.

• Citrus greening (HLB)

  Blotchy, uneven yellowing that isn't the same on both halves of a leaf; small, lopsided, bitter fruit that stays green at the bottom; twig dieback.

  What to do: There's no cure. Keep the tree well fed with a complete citrus fertilizer and micronutrients to slow decline.

  A regulated disease in Florida, Texas, California and elsewhere. If you suspect it, contact your county extension office or the state agriculture department.

• Citrus canker

  Raised, corky brown spots with a yellow halo on leaves, twigs and fruit; fruit may drop early.

  What to do: Copper sprays protect new growth and young fruit.

  Regulated in several states. Report suspected cases to your extension office.

• Citrus leafminer

  Silvery, winding tunnels in young leaves, which curl and twist.

  What to do: Mostly cosmetic on mature trees; leave them be.

• Phytophthora root rot

  Small, pale, wilting leaves, thin canopy and branch dieback; roots are black and brittle instead of white.

  What to do: Water less and improve drainage.

• Algal leaf spot

  Raised, rusty-orange velvety spots on leaves and twigs.

  What to do: Copper spray in summer if it's heavy.