Plant Name:  Engelmann Oak Tree

Botanical Name:  Quercus engelmannii

Origin: Native to Southern California

Height/Physical Description:  40 to 50 feet in height and twice as large in width, evergreen, with thick, leathery, bluish-green oval or oblong leaves that have smooth edges.  

Special Attributes:  Beautiful canopy with large spreading growth habit.  It produces 1¼ inch long acorns that are round-tipped, half enclosed in a warty cap.  This is a California native.  Not susceptible to “sudden oak death.”

Purchasing:  Private nurseries and online.

Planting Requirements: No special soil is required except to have good drainage.  Plant in Fall or Winter to allow tree to get established.  

Watering:  Young trees require a moderate amount of water until established especially between the months of March through May to support the tree’s new growth.  Do not water next to the base of the tree as this could result in root diseases.  Water only over the outer third of the root system to encourage roots to grow outward.  

Fertilizing:  Compost can be added but away from the base of the tree.

Harvesting:  Acorns form and can be harvested in the Fall.

Pruning:  Periodic grooming may be required to remove dead or cross branches.  Prune trees only when they are dormant.  For deciduous trees, prune when leaves have completely dropped off; for evergreens, prune during the dry season (mid to late Summer) to avoid mildew and fungal diseases.

Pest:  Oak moths, galls, mites.  

Diseases:  The following are common diseases that occur in all oak trees:  oak root fungus (Armillaria mellea) and sudden oak death (phytophthora ramorum).  

Additional Information:  Engelmann oak is less susceptible to sudden oak death.  Sunset zones 14-24.