Accent
Candelilla
Euphorbia antisyphilitica · Euphorbiaceae
Also called: Wax Plant, Wax Euphorbia
Candelilla (Euphorbia antisyphilitica) is a very low-water accent well suited to Tucson and the low desert. It grows to 2-3 ft H x 2-3 ft W, with a slow growth rate.
Candelilla at a glance
- Water use
- Very Low (established)
- Sun
- Full sun to light/reflected heat; tolerates full reflected sun. Will accept light shade but grows leggier and less dense.
- Mature size
- 2-3 ft H x 2-3 ft W
- Growth rate
- Slow
- Bloom
- Small white to pinkish flowers borne along the upper stems., Mostly spring and fall, sporadically after rains; flowering is subtle and not the main ornamental feature.
- Cold hardiness
- Hardy to about 10-15°F (USDA zones 8-11); root-hardy and recovers from occasional brief lows. Tip damage possible below ~20°F.
- Soil
- Requires excellent drainage; thrives in lean, rocky, sandy or decomposed-granite soils. Tolerates poor, alkaline native desert soils. Rots in heavy, poorly drained or overwatered soils.
- Native range
- Chihuahuan Desert of West Texas and northern Mexico (Coahuila, Chihuahua); not native to the Sonoran Desert but well adapted to Tucson's low desert.
- Best used as
- Accent / focal point, Container plantings, Rock and cactus gardens, Xeriscape and low-water designs, Mass groupings for vertical texture
- Wildlife
- Minor flower interest for bees and small pollinators; leafless stems offer little browse value, and the latex deters most herbivores.
- Toxicity
- Milky latex sap is toxic and a skin/eye irritant; contains caustic compounds historically used for candle and wax production. Keep away from eyes and mucous membranes; wear gloves when cutting. Toxic if ingested.
How to grow Candelilla in Tucson & the low desert
Watering
Established plants need very little supplemental water — deep soak roughly once a month in summer, little to none in winter. Overwatering causes rot, so let soil dry thoroughly between irrigations.
Fertilizer & nutrients
Essentially none required; thrives on lean soils. A single light application of balanced or low-nitrogen fertilizer in spring is more than enough if any feeding is desired.
Pruning & care
Little to no pruning needed. Remove dead, frost-damaged, or errant stems in spring; avoid shearing, which spoils its natural clumping habit.
Notes
A nearly leafless succulent-stemmed accent forming dense clumps of slender, pencil-like, grey-green, wax-coated upright stems. The waxy coating is the source of commercial candelilla wax. Valued in Tucson landscapes for striking vertical line and architectural texture in cactus and succulent compositions; extremely heat- and drought-tolerant once established.
Sources: University of Arizona Cooperative Extension; Arizona-Sonora Desert Museum; AMWUA 'Landscape Plants for the Arizona Desert'; Tohono Chul / Tucson Botanical Gardens