You may think that when you purchase a home in La Paz, Mexico that your green thumb will not be required south of the border. It may be arid country with over 340 days of sunshine per year and an average 16 days of rainfall, but owning real estate in Mexico does not mean you necessarily have to forgo your love of gardening -- you just need to learn how to grow different kinds of plants. You may be pleasantly surprised to learn how many varieties of cactus and wildflowers thrive in Mexico's Sonoran Desert.

The hottest of our North American deserts, the Sonoran is an arid region covering 120,000 square miles in southwestern Arizona, southeastern California, most of Baja California Sur, and the western half of the state of Sonora, Mexico. Despite the common stereotype that it does not rain in deserts, the Sonoran Desert is considered the wettest desert in the world, receiving 3 to 15 inches per year, and it contains more than 2000 native plant species, including plants from the agave family, palm family, cactus family, legume family, and many others. The Sonoran Desert has the greatest diversity of vegetative growth of any desert worldwide! That's a lot to build a garden with! This week, we examine the various types of cacti native to this corner of Mexico, and next week we will explore the wildflowers of the desert. You will be surprised at the variety and colors of flowers that flourish in the desert!



No discussion about cacti of Baja should begin with anything other than the Cardón. The cardón cactus (Pachycereus pringlei) is the world's largest cactus and is nearly endemic to the deserts of the Baja California peninsula. Some of the largest cardones have been measured at nearly 21 meters (70 feet) high and weigh up to 25 tons. These very slow growing plants are also extremely long-lived, and many specimens live well over 300 years. 'Cardo' means 'thistle' in Spanish. It is said that when Hernando Cortes attempted to establish a settlement in Baja in 1535, the many spiny cacti earned it the name 'Isla de Cardón', because at the time, they believed the peninsula was an island. In Latin, 'pachy' means thick and 'cereus' means waxy. One has only to see the thick arms of this pale gray-green, waxy skinned cactus to understand what the traveling American botanist, Cyrus Pringle, meant when he named the species.

Many first time visitors to Baja mistake this giant cactus for the ecologically similar saguaro cactus, however, while the saguaro live in the Sonoran Desert, they do not live in Baja specifically. The reverse is also true: while there are a few stands of cardón found across the Gulf of California on the Mexican mainland, they seldom occur near the saguaro. The main trunk of the cardón may have as many as 25 vertical branches, up to 1.5 meters (5 feet) in diameter. In older plants the branches are usually taller than the trunk. The cardón are especially spiny when they are smaller, to protect them from predators. As they grow older, many of the spines fall off and are not replaced.

The lower trunks of older plants turn gray, and a cracked, woody bark makes them look like the thick legs of an elephant. Woody vertical ribs allow the columnar cactus to expand and contract like an accordion, storing the water it needs to survive in the arid conditions. These cacti have developed extensive, shallow root systems which quickly capture the brief, but torrential rains of the region. A large cardón may store over a ton of water in the fleshy, pulp-like tissues of its trunk. In order to support this great weight, the large cactus has an interior framework of hardwood vertical rods, lightweight, yet extremely strong, which act to stiffen the ribs. This amazingly tough hardwood skeleton has allowed the cardón to become the largest cactus species, able to thrive in the very harsh climate of the Baja California's Sonoran Desert. From March through June, flowers appear on the upper tips of stems, especially stems with warm, southern exposure. Flowers open in the afternoon, stay open all night, then close about mid-morning the next day.

Other cactus found in the Sororon desert include (in alphabetical order), Barrel Cactus, Beavertail Cactus, Century Plant, Chain Fruit Cholla, Cholla Cactus, Claret Cup Cactus, Desert Christmas Cactus, Datil Yucca, Fishhook Cactus, Hedgehog, Mojave Yucca, Night-Blooming Cereus, Organ Pipe Cactus, Senita Cactus, Soaptree Yucca. Any of these will survive well in your Mexican garden.