Growth of Five Species of Mexican Oaks at the Los Angeles County Arboretum & Botanic Garden

Donald R. Hodel, Emeritus, University of California Cooperative Extension, Los Angeles

James E. Henrich, Los Angeles County Arboretum & Botanic Garden, Arcadia, California

With more than 160 indigenous species of Quercus, Mexico is the primary center of oak diversity in the world. In late 2001 co-author Hodel visited northeastern Mexico and collected seeds of several, mostly evergreen species. Hodel germinated the seeds and grew them on. In 2005 the seedlings, in one- or two-gallon containers and just a few feet tall, were planted out at The Arboretum. After 15 years all have grown remarkably well, clearly demonstrating their adaptability and suitability to the southern California landscape. They received no special care other than an occasional irrigation and a minimum of structural pruning to achieve proper structure. They have flowered and fruited and have attained from 35 to 50 feet in height. Most had adequate, if not superb, conformation and structure with little or no pruning. All would make superb ornamentals for California; much prized for their strong, robust growth of good to excellent conformation with few or no structural defects, handsome leaves, mostly evergreen habit, and suspected marginally low-water use.