Deserts can be beautiful. They can also be deadly, especially for those who are unprepared for the environment. A good way to enjoy the beauty of a desert without suffering through the dangers of walking about in a inhospitable landscape is to create a desert garden. This idea is especially beneficial for people who live in dry, barren areas where water is precious.
Desert plants do require water. Indeed, some of them have far reaching roots that will grow just beneath the surface over a wide area in search of the merest drops of that precious elixir. Sadly, this can cause these beautiful dry weather plants to bloat themselves with excessive water if they are near an irrigation system. Just like the kid who reaches for the candy dish a little too often, or (more aptly) drinks too much soda, certain of the large desert plants, such as the Joshua tree or the pachycereus family of cacti, those towering, prickly behemoths that dominate old movies about the American Southwest.
This does not mean that you should panic if you accidentally over-water your baby Joshua tree or elephant cactus, but it does indicate that you should not plant them out of doors near an irrigation system. Some of the cacti are so adapted to seeking moisture and nutrients, even enclosing water behind a concrete barrier might not be enough because they have adapted to the extent that their roots can break down rock for nutrients, enabling them to live in the most inhospitable places.
But if your back-yard borders on open desert, then these dry country giants could be the perfect selections for your “greenspace.”
- Joshua Tree (yucca brevifolia). While perhaps not the largest or even the most beautiful of the tree yuccas, it probably has the most colorful history. Moreover, thanks to recent forest fires, as well as climate change, and human encroachment, environmentalists are worried about the Joshua tree’s future. It is native to the Mojave Desert, which tends to have a specific soil type, so your Joshua tree might need some supplemental feedings for good health. It likes a soil that is alkaline, with a good dose of salt. It does need water, but once established it can process even the most minute amounts of atmospheric moisture using its upward pointing rosettes of leaves. In the northern hemisphere, it will bloom in the spring, sometime around May. To produce seeds, it requires a specialized pollinator, the yucca moth.
- Elephant Cactus (Pachycereus pringlei). Purported to include one of the tallest cactus plants to be found anywhere, elephant cactus grows a tall, single stalk. Like the Joshua tree, it loves water and will send out a web of feeder roots that actively look for both water and nutrients. It has the amazing property of being able to grow on bare rock, digging in with its little rootlet toes and drawing nutrients out of the rock itself. That does not mean it does not like soil. It does. But it gives this cactus the happy property of being able to grow just about anywhere. So if you live in an area where your soil layer is extremely thin, as well as being porous, sandy, and generally inhospitable to life, your elephant cactus is likely to be a happy camper. When sufficiently mature, your plant will have white blossoms that are about three inches across. If properly pollinated, the blossoms will give way to an edible fruit. The Comcaac ate (and possibly still do eat) the fruit, and ground the seeds to use as flour. They also chopped down the tall cacti and used the logs as building material. The fleshy stalk of the elephant cactus is high in alkaloids, and should not be eaten.
- Candelabra Cactus (Pachycereus weberi). This is, as you might have guessed from the scientific name, a cousin of pringlei. The candelabra cactus does not grow quite as tall as the elephant cactus, but it does reach a respectable size. Unlike its cousin, it will develop multiple arms, giving it the appearance of a giant candelabra. In season, it will grow yellow and white flowers that bloom only at night, and are pollinated by bats. The oblong fruit is edible. The indigenous people of Oaxaca (which included several distinct groups) ate the fruit, used it to make a fermented drink, and ground the seeds for flour. They used the giant cactus logs in making houses and other buildings. P. weberi does not have quite the voracious appetite for water that is shared by the Joshua tree and the elephant cactus, but it still needs good drainage. It is happy in sandy soil, and if grown in a pot, will do well in any standard cactus mix.
These three desert giants can all be grown in pots in the early stages of their lives. Thanks to climate change, plant poaching, and other considerations, always make sure that you obtain your plants from a grower who is licensed to handle rare or endangered plants. That way, you can be sure that your plant babies are responsibly sourced and have not been stolen from a park or an area where the ecology could be compromised by plant poaching.
When you are exploring, looking at native plants in their habitat, always follow the following maxim: take nothing but pictures, leave nothing but footprints. Oh, and carry plenty of water. You, unlike the plant giants discussed here, need lots of potable water when exploring their native habitats.