Tropical
Ixora
Ixora coccinea · Rubiaceae
Also called: Jungle flame, Jungle geranium, Flame of the woods
Ixora (Ixora coccinea) is a high-water tropical well suited to Tucson and the low desert. It thrives in full sun to part shade, with a slow to moderate growth rate.
Ixora at a glance
- Water use
- High (established)
- Sun
- Full sun to part shade; in Tucson it strongly benefits from morning sun with afternoon shade to avoid leaf scorch in summer heat.
- Mature size
- Typically 2-4 ft tall and wide in cultivation/containers in Tucson (to 4-6 ft in ideal tropical conditions)
- Growth rate
- Slow to moderate
- Bloom
- Clusters of red, orange, pink, or yellow tubular flowers (most common is scarlet-red), Warm months, repeat-flowering spring through fall in heat
- Cold hardiness
- Very frost-tender; damaged below ~45 F and killed by frost. Must be protected, brought indoors, or grown as a container plant moved to shelter in winter in USDA 9a-9b.
- Soil
- Demands acidic (pH ~5-6.5), rich, well-draining soil. Tucson's alkaline native soil and caliche are poorly suited; grow in amended raised beds or pots with acidic potting mix.
- Native range
- Southern India and Sri Lanka (tropical Asia)
- Best used as
- Container/patio specimen, Tropical accent in sheltered microclimates, Low hedge in frost-free spots
- Wildlife
- Tubular flowers attract butterflies and hummingbirds.
- Toxicity
- Generally regarded as non-toxic to humans and pets.
How to grow Ixora in Tucson & the low desert
Watering
Keep soil consistently moist; water 2-3 times per week in summer heat and never let it dry out completely. It is not drought-tolerant and is best grown in a container or sheltered, well-amended bed.
Fertilizer & nutrients
Heavy feeder needing acidic conditions. Use an acid-loving-plant fertilizer (azalea/camellia type) monthly in the growing season; supplement with iron and micronutrients to combat chlorosis. Tucson's alkaline water and soil cause persistent yellowing without acidification.
Pruning & care
Pinch tips to encourage branching and remove spent flower clusters. Light shaping after bloom flushes; avoid hard pruning, which removes flower buds.
Notes
A challenging choice for Tucson and not a low-desert-adapted plant. It struggles with alkaline soil/water (chronic iron chlorosis) and summer sun scorch, and is freeze-sensitive. Best treated as a high-maintenance container tropical with afternoon shade, acidic media, regular iron, and winter frost protection.
Sources: University of Florida IFAS Extension (Ixora coccinea); University of Arizona Cooperative Extension (chlorosis / alkaline soil guidance); Pima County Master Gardeners