Pronounciation: CI-trus X tan-GEL-o

Hardiness zones:
Sunset 12-24
USDA 9-11

Landscape Use: Accent, edible gardens, residential fruit tree, mesic and oasis landscape design themes, attracts bees.

Form & Character: Upright, rounded, symmetrical, domestic, colorful, abundant.

Growth Habit: Evergreen, woody perennial large shrub to small tree, moderate growth rate to 20-feet tall with similar spread.

Foliage/Texture: Medium green, glaborous and leathery leaves are oblong, elliptical, or oval, tapering to a blunt tip, 3-inches long, 1.5-inches wide, petiole wings are slim, lamina midvein is prominent, sometimes sharp, stipular spines are present; medium texture.

Flowers & Fruits: Flowers are borne in small clusters in leaf axils, flower buds are purplish, but open flowers have five distinct white petals, up to 2-inches across, highly fragrant. Flowers are hermaphroditic (has both male and female organs), self fertile, pollinated by bees; fruits are a hesperidium berry, globose to oblong, 3- to 5-inches long, fruit apex always nippled, exocarp ripens to orange with smooth to bumpy rinds dotted with oil glands, endocarp having 10 to 14 segments (carpels) sometimes containing seeds.

Seasonal Color: Bright orange fruits typically ripen in winter.

Temperature: Cold hardy to 26^oF and heat intolerant above 118^oF. Significant heat stress injury (leaf yellowing and necrosis) occurs above 112^oF, especially if located in full western sun.

Light: Full sun to filtered shade or some shade from western summer sun, no full shade.

Soil: Tolerant, but well drained soils is essential. Maintaining adequate to optimal soil fertility levels crucial for successful culture of tangelo. Generally, tangelo like other citrus will need to be fertilized with a balanced, complete fertilizer containing micronutrient supplements (Fe, Zn, and Mn) three times each year (January, May and September).

Watering: Moderate and consistent patterns of supplemental irrigation are neccesary for successful desert culture, but irrigation frequency and duration varies with time of year and soil texture. In general, flooded, berm irrigations are superior to drip irrigation (less accumulation of soil salts in the rhizosphere).

Pruning: Only infrequent, 'light' pruning is required. Pruning strategies should always NOT incude crown raising because all Citrus taxa are HIGHLY prone to trunk scald if exposed to direct summer sunlight.

Here's a sustainable tip: If the 'Horticultural clods of Phoenix' (aka 'Hort clods') have wandered (like migrant nomads) into your yard and 'lolly popped' your tangelo tree by raising the crown base to expose its trunk to direct sunlight, then promptly respond by painting the trunk surface with a mixture of white flat latex paint and water (1:1 ratio) to protect the exposed trunk from summer sunscald injury (increased albedo = lower trunk temperatures).

Propagation: Softwood or semi-hardwood stem cuttings, grafting, budding.

Disease and Pests: All citrus including tangelo are prone to numerous, well-documented, mostly soil-derived, biotic and abiotic pressures. Citrus greening is a serious bacterial disease vectored by two psyllid insects.

Additional comments: Tangelo is a wonderfully productive citrus tree for Arizona lower desert residential backyard gardens. There are three tangelo cultivars that perform well in the lower Arizona desert, 'Allspice', 'Orlando' and 'Minneola'.