Bitter orange
Also known as
Seville orange, Sour orange, Bigarade orange, Bigarade
Keep this plant’s care guide close at hand.
Get the appAbout Bitter orange
Citrus × aurantium, commonly called bitter orange or Seville orange, is an evergreen citrus tree valued for its fragrant blossoms and aromatic, bitter peel. A hybrid of pomelo (C. maxima) and mandarin (C. reticulata), it grows 3–10 m tall, with glossy, dark green leaves bearing distinctly winged petioles and stout spines on twigs. Spring flowers are intensely perfumed (orange blossom) and distilled for neroli oil; leaves and young twigs yield petitgrain. The fruit is round to slightly flattened, with a thick, pebbled rind rich in essential oils and a sour, bitter pulp. While too bitter for fresh eating, it is prized for marmalades, candied peel, marinades, and liqueurs, and as a traditional citrus rootstock. Compared with sweet orange, it is relatively cold-tolerant and amenable to container culture given strong light and free-draining, slightly acidic soil. Outdoors it suits warm-temperate to subtropical climates; indoors, it needs bright sun and regular pruning to maintain shape and encourage flowering.
Taxonomy
Properties & Requirements
How to care for Bitter orange
Water
Water deeply, then allow the top 2–5 cm of potting mix to dry before watering again. In containers, irrigate until 10–20% runoff and empty saucers promptly. Frequency varies with light, temperature, and pot size—typically every 5–10 days in warm, bright conditions and less in winter. Consistent moisture supports flowering and fruit fill, but avoid waterlogging, which causes root rot and leaf drop. Use a fast-draining, airy mix and increase watering during hot, windy spells.
Light
Provide full sun for best flowering and fruiting: outdoors, 6–8+ hours of direct sun; indoors, a south- or west-facing window with maximum exposure. Rotate the pot weekly for even growth. If natural light is insufficient, supplement with LED grow lights delivering roughly 250–500 μmol·m⁻²·s⁻¹ for 12–14 hours daily. Harden plants to outdoor sun over 7–14 days each spring to prevent scorch. Insufficient light leads to leggy growth, weak bloom, and poor fruit quality.
Nutrients
Use a citrus-specific fertilizer high in nitrogen with micronutrients (iron, magnesium, manganese, zinc, boron). During active growth (spring through early autumn), feed potted plants every 2–4 weeks at half strength or apply a controlled-release formulation per label rates. Reduce or stop feeding in winter. Maintain slightly acidic soil; if leaves yellow between veins, apply chelated iron and check pH. Flush pots periodically to prevent salt buildup, and avoid overfertilizing, which can cause leaf tip burn and soft, pest-prone growth.
Temperature
Ideal temperatures are 18–26°C by day and 10–16°C by night. Bitter orange tolerates brief dips close to freezing when established outdoors, but protect container plants from frost; bring them inside when nights fall below 5–7°C. Provide good airflow in hot weather and some afternoon shade where temperatures exceed 35°C to limit stress and fruit drop. Avoid cold drafts indoors and sudden swings in temperature, which can trigger leaf abscission and poor bloom.
