By Don Rideout, Native Plant Gardener and CNPS Volunteer
Our warming climate is expected to force a number of species to either adjust their ranges or face extinction. This could mean that plants from Baja that are currently uncommon in San Diego County may in the future be more appropriate for our region. Several Baja plants are already popular in many gardens for good reason: they tend to be extremely drought tolerant, hardy, and beautiful. There are lots to choose from. Some are well-known, while others are more obscure; some are found north of the border while others are Baja endemics. Not all of these are from the California Floristic Province, but all of them are good choices for San Diego gardens. There isn’t space to list them all or give too many details here, but if you’re interested in any of these, click on the green title of each plant to visit the Calscape link. Here are a few to consider for your garden.
Shaw’s Agave (Agave shawii) is already in use in many gardens. Its garden value is in its great sculptural form. Don’t count on flowers—like other agaves, it can take decades to bloom. It spreads by growing new rosettes around the original one. A drawback of the plant is its lethal spines on the tips of the leaves, so think carefully about where you plant it. I like to trim the tips off mine so I don’t impale myself while working around it.
Golden Cereus (Bergerocactus emoryi) is a cholla-type cactus often found with Shaw’s Agave on the coast, starting around Rosarito. The spines are golden color and seem to glow in the sun. Like other chollas, it has nasty spines. If given room to spread, it will. For both of these reasons, use discretion about where you plant it. The flowers of this cactus are small and yellow-green and not very conspicuous, so its garden value is mainly in the color and sculptural form of the plant itself. Best near the coast.
Elephant Tree (Bursera species) This is one of the most unique genera of Baja, with several species from different parts of the peninsula. Bursera microphylla is probably the most commonly available. Anza-Borrego is the northern limit of its range. Other interesting species are B. fagaroides and B. hindsiana. Any of these will do well in a container or in the ground. Use with boulders and gravel mulch. Best used inland—they like heat.
Baja Fairyduster (Calliandra californica) Here’s one with no spines and terrific flowers! It blooms almost year-round. It is native to the central desert and also some islands, so it’s versatile for both coastal and inland gardens. Hummingbirds will thank you.
Cliff Spurge (Euphorbia misera) is a great companion to cactus, dudleyas, and other succulents in a rock garden setting. When dry it looks like all stems, but when it gets a little water it produces small round leaves and tiny flowers. Best near the coast.
Baja California Spurge (Euphorbia xantii) is a larger shrub to 10 feet tall, consisting of a tightly packed cluster of thin stems, green when young and becoming woody with age. The flowers, which appear in spring, are pink and small but numerous. This one is very easy to start from cuttings. It takes pruning well to control the height or spread, but watch out for the white sap—it’s somewhat toxic.
Cardón Cactus (Pachycereus pringlei) is a columnar cactus that can eventually get quite large but is slow growing. Its upright form provides a nice contrast to lower shrubs. Best used inland with boulders and gravel mulch.
Baja Birdbush (Ornithostaphylos oppositifolia) is found in the border region where it is threatened by encroaching urbanization and border enforcement activities. A beautiful, rare shrub related to manzanitas, the Baja Birdbush would be a wonderful addition to any San Diego garden. Its growth rate is slow, so be patient.
Small Leaved Rose (Rosa minutifolia) is another really rare plant in the wild, found from the border down to around El Rosario. It is quite different from roses you may be used to—highly drought tolerant, remaining rather small, and preferring to associate with cacti and succulents. It will drop its leaves when dry but will leaf out and even bloom at any time if given some water.
Tapertip Dudleya (Dudleya attenuata) is found from the border region down to around El Rosario. It has slender leaves with a round cross-section, giving it a resemblance to other Dudleyas such as D. edulis and D. hassei. Does great in a container or in the ground, and mixes well with other plants.
Baja Bush Snapdragon (Gambelia juncea) has showy red, tubular flowers that hummingbirds love. There are two horticultural varieties to choose from: ‘Gran Cañon’ (selected from Cedros Island by Santa Barbara Botanical Garden) and ‘Punta Banda’ (selected from its namesake location south of Ensenada by Tree of Life Nursery).
References:
Baja California Plant Field Guide (3rd edition); Rebman and Roberts; (2012) Sunbelt Publications
Plant Guide: Maritime Succulent Scrub Region, Northwest Baja California, Mexico; Riley, Rebman, and Vanderplank; (2015) Botanical Research Institute of Texas