Guaiacum coulteri

A gnarly, evergreen and slow growing shrub or small tree native to the gravelly plains of western Mexico. Also called Lockwood, Tree of Life and Wood of Life.

Flowers: J F M A M J J A S O N D
Status: Near Native
Origin: A dry forest hardwood species endemic to the mountainous semi-tropical, deciduous forest Pacific coast regions of western Mexico from Sonora south to Oaxaca and also in Guatemala.
Family: Zygophyllaceae
Size: 10′ x 10′
Sun: Full to part sun
Watering: Supplemental. Prefers dry winters
Growth Rate: Slow
Soil: Gravely and well drained are best
Temperature: Hardy to 25 degrees F
Pruning: Prune conservatively to shape depending on landscape use, mostly to direct spread and control pendulous branching habit
Disease and Pests: None
Uses: The red fruit attract birds that disperse the seeds. 
Notes: Rangy when young. Branch tips may be damaged by temperatures below 30 degrees F. Extremely drought tolerant. Guaiacum coulteri has been extensively harvested in its southern native range. Over exploitation for timber in conjunction with habitat loss and a slow rate of regeneration has left G. coulteri threatened and has led to its listing on the IUCN Red List of Threatened Species and protection under CITES.

In Maricopa County the average first frost date varies from Nov 21st to Dec 12th. In Tucson the average first frost date is Dec 3rd.

  • Keep plants well watered
  • Place plants in a protected microclimate
  • Protect by covering plants, adding heat or increasing air circulation
  • Do not prune frost damage until plants begin growing

For more info: Protecting Frost Sensitive Plants


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