Far Afield: Plants of Mediterranean Baja

There has been much talk lately in the news about California’s stagnant population. For the first time in our state’s history, new immigrants and births have been balanced by folks leaving. Among the emigrants’ complaints are housing prices and cost of living. Few – if any – would list our climate as a motivating factor in departing for Colorado or Texas. How could they? The mild winters and dry, sunny summers of our Mediterranean climate are truly hard to beat.

There are a few surprising things about this unique climate zone. One is that much of California does not have a Mediterranean climate (think Fort Bragg, Lake Tahoe, or Needles). Another is that it extends beyond California’s borders. Starting around Ashland, Oregon, the zone widens to include the Central Valley, Sierra foothills and coast ranges. At Los Angeles, the zone is pushed to the coast by the interior deserts. At the Mexican border it continues to narrow, ending about two hundred miles south at the Pacific coast of Northern Baja. The Mediterranean climate zone reaches its southern extreme on a handful of Pacific islands.

More than a great place to live, work or play, this climate zone also establishes the borders of many, many plants adapted to mild winters and dry summers. When considered as a plant community, the Mediterranean climate zone is referred to as the California Floristic Province. For gardeners within the Province, it presents an enormous palette of planting possibilities. Many of the plants grow within the border of the Province, but outside California.

Here are a few such plants from the Mediterranean portion of Northern Baja, Mexico. These have shown tolerance to our winter cold and have thrived in gardens here in San Jose. Consider these for what remains of the winter planting season!

Solanum hindsianum - Baja California Nightshade

Solanum hindsianum, Baja California Nightshade: This striking nightshade is native to much of Baja California and northwest Mexico. A small population grows in Pima County, Arizona. It is absent from California. It grows as a rounded, open, shrub to about five feet, with nearly white branches and foliage. Unusual for a nightshade, the plant is protected by stout thorns on the branches. In spring, large purple flowers appear which stand out dramatically against the light green foliage. Baja nightshade is said to be damaged by frost at about 25F, but I have not seen this in a specimen that I have kept in a pot for several years in my San Jose garden. Plant this desert species against a south facing wall, or under a tree where it will receive overhead protection but not shade. Baja nightshade is drought tolerant, but like many desert species it responds well to occasional summer water.

Gambelia juncea 'Gran Canon' - Baja snapdragon 'Gran Canon'

Gambelia juncea, ‘Gran Canon’ Baja Snapdragon: The Baja bush snapdragon is found in many regions of Baja California. This selection is from the Gran Canon of Cedros Island which lies off the western coast roughly mid-way down the peninsula. Cedros Island is one of the nine Mexican Pacific Islands. The moist, cool air from the Pacific Ocean couple with scant rainfall to provide a climate that places these islands as part of the California Floristic Province (i.e. the region characterized by a Mediterranean climate). Like the Channel Islands of California, the Mexican Pacific Islands offer many plants that do quite well anywhere within this climate zone as long as prolonged frost is avoided. Baja bush snapdragon grows as an open fountain of upright green branches punctuated by tiny green leaves. In the spring and early summer tubular red flowers appear, attracting hummingbirds. A sunny, hot location with well-draining soil seems best. Occasional summer water enhances the appearance of the
Baja bush snapdragon although it is quite drought tolerant.

Calliandra californica - Red fairy duster

Calliandra californica, red fairy duster, is native to Baja California but has much to contribute to the dry garden. It grows in a large, rounded form that is fairly open which allows the delicate, feathery leaves to be appreciated. The flowers are a bright red and appear generously in the spring and then intermittently until winter. It reminds one of a small acacia, to which it is closely related. A sunny spot with good drainage is important. Very little water is needed once the red fairy duster is established, though it is tolerant of occasional summer water.

Brahea armata - Mexican blue palm

Brahea armata, Mexican Blue Palm: This attractive palm grows in Baja, Mexico, just south of the border. Its range falls within the California Floristic Province. Mexican blue palm survives in arid settings by accessing the subterranean waters of canyons and arroyos. It is one of many Brahea species endemic to Mexico. The leaves are similar to those of the Mexican fan palm, Washingtonia robusta, but have a silvery blue hue. It slowly grows in typical palm fashion to a height of thirty feet. The summer flowers are a cascade of white. The fruit matures from green to yellow. Although a southern species, Mexican blue palm is quite tolerant of cold temperatures. This is an adaptable, and widely planted palm. Occasional deep watering seems best for established plants.

Rhus lentii - Pink Flowering Sumac

Rhus lentii, Pink Flowering Sumac, is native to northwestern Baja down to Cedros Island. Its range corresponds to the southern limit of the California Floristic Province, i.e. those areas of the Pacific coast with a Mediterranean climate. This sumac grows in a round or spreading form to about seven feet or so. The leaves are a gray-tinged waxy green with toothed edges. In many ways this shrub looks like a combination of lemonade berry, Rhus integrifolia, and sugar bush, Rhus ovata, with which it shares portions of its range. In winter and early spring it is covered with prominent pink flowers which show nicely against the dusky foliage. The fruit are little red disks like other members of the genus. Pink flowering sumac appreciates well-draining soil and a sunny site. It is cold hardy to at least 25F.

Euphorbia xanti - Baja SpurgeEuphorbia xanti - Baja Spurge

Euphorbia xanti, Baja Spurge: The Euphorbia genus is worldwide in distribution, represented by plants of widely varying forms and cultural needs. The Baja spurge is one of 50 species native to the Baja Peninsula. It grows as an upright shrub with a woody base and linear green branches with small leaves. The branches form a dense network overtime as the shrub quickly grows to eight feet or so. The small flowers appear throughout the growing season. Baja spurge expands quite quickly by underground rhizomes, especially if supplemental irrigation is provided, which is recommended to keep the plant looking its best. Accounts indicate that Baja spurge is hardy to 25F. Note: the sap of euphorbias is toxic. Avoid contact with skin and eyes.