Citrus
Sour (Seville) Orange
Citrus x aurantium 'Seville' · Rutaceae
Also called: Seville Orange, Bitter Orange, Marmalade Orange
Sour (Seville) Orange (Citrus x aurantium 'Seville') is a low-water citrus well suited to Tucson and the low desert. It thrives in full sun. Expect white, intensely fragrant blooms Heavy bloom in spring.
Sour (Seville) Orange at a glance
- Water use
- Low (established)
- Sun
- Full sun. Tough and adaptable; tolerates reflected heat better than most citrus once established.
- Mature size
- 20-30 ft tall and 15-25 ft wide; a substantial rounded evergreen tree.
- Growth rate
- Moderate.
- Bloom
- White, intensely fragrant, Heavy bloom in spring (Feb-Apr); the powerful orange-blossom fragrance is a signature of Tucson spring. Fruit colors orange and persists fall through winter.
- Cold hardiness
- Cold-hardy for citrus, roughly to the low 20s°F; reliably hardy in Tucson (USDA 9a-9b). Mature trees shrug off normal Tucson frosts.
- Soil
- Wide tolerance, including heavy and alkaline desert soils, as long as drainage is adequate. One of the most soil-adaptable citrus, which is why it is the classic citrus rootstock.
- Native range
- Hybrid of Southeast Asian origin (C. maxima x C. reticulata); long naturalized in the Mediterranean. Not native to Arizona, but a long-established heritage street/landscape tree in Tucson and Phoenix.
- Best used as
- Ornamental/heritage shade and street tree, Fragrant spring bloom, Seville marmalade and preserves, Citrus rootstock, Peel oil and zest for cooking
- Wildlife
- Fragrant blossoms are a major nectar source for bees; dense evergreen canopy shelters birds.
- Toxicity
- Fruit is edible but extremely sour/bitter, used cooked (marmalade), not fresh. Bitter orange contains synephrine; peel/oils and seeds are best not consumed in quantity by pets. Sharp thorns are a hazard for kids and pets.
How to grow Sour (Seville) Orange in Tucson & the low desert
Watering
Deep, infrequent irrigation wetting the root zone to ~2-3 ft. Every 7-14 days in summer, every 3-4 weeks in winter. Established heritage trees are notably drought-tough but fruit and canopy improve with regular deep watering.
Fertilizer & nutrients
Citrus fertilizer with nitrogen plus micronutrients (zinc, iron, manganese); split nitrogen into thirds applied about Feb, May and Sept per UA Extension. Less demanding than sweet orange; correct alkaline-soil chlorosis with chelated iron/zinc.
Pruning & care
Low-maintenance. Remove deadwood, suckers and crossing branches in spring after frost; can be limbed up as a shade tree or sheared as a tall screen. Thorny, so wear gloves.
Notes
The traditional Tucson/Phoenix landscape sour orange. Prized for marmalade and its drought- and heat-tolerance. Drops abundant fruit, so site away from walkways/pools to reduce cleanup. Widely used historically as the rootstock for sweet citrus.
Sources: University of Arizona Cooperative Extension - Oranges for Southern Arizona (az1850); UCR Givaudan Citrus Variety Collection - Seville sour orange (CRC 3856); Purdue NewCROP - Sour Orange