Growing herbs in the desert can be challenging–and easy, according to one expert who is well-versed in arid-region gardening. “The deserts of Las Vegas and Phoenix have extreme temperatures,” says Brandi Eide, “not to mention low annual rainfall, which for Las Vegas, is about four inches a year and, in Phoenix, about seven.”
You can’t, says Eide, just sprinkle a few seeds in the ground in a desert climate and expect things to flourish like they would in the rich soils of the Midwest or California’s Central Valley. But with a bit of effort, you should be able to grow plenty of mint for those mojitos and enough basil to make a freezer’s worth of pesto.
Eide should know. She’s the botanical garden supervisor at the 180-acre Springs Preserve in Las Vegas, where, among many things, she cultivates the vegetable and herb gardens. Eide has also held similar positions at the Desert Botanical Garden in Phoenix, the Phoenix Zoo and at UC Berkeley’s botanical gardens.
She has a few tips for desert dwellers who want to grow herbs in either garden beds or in pots.
Eide starts with soil, believing that good soil creates happy plants. “Desert soil is mostly minerals, “ Eide explains, “so if you’re planting something in your garden, the soil needs to be amended with some well-draining nutrients, which you can bring in by the truckload for gardens or get by the bag for pots.”
She steers away from anything that contains too much peat. “Peat is hydrophobic, which means it dries out quickly and isn’t a good thing for the desert. Plus, I don’t think it’s a very sustainable resource.”
Proper watering is also important for growing herbs. “If you’re growing herbs in a pot, water enough so that it drips out the bottom. That helps flush the salts past the herbs’ root zone. You want to keep the pots moist, but not soggy.”
For herbs grown in the ground or a raised bed, Eide recommends deep–but not necessarily frequent–watering. “You want to make sure that the water gets down several inches below the soil surface to encourage deep root development. That helps the herbs tolerate the heat. If you just sprinkle water on the soil surface, the plant’s roots will stay near the surface and be more vulnerable to the heat.
Eide recommends feeding herbs with organic fertilizers during their growing season. “If you fertilize just before the onset of heat or frost, it stimulates new growth and those tender shoots are vulnerable to temperature extremes.”
When and where to plant are other questions that come up with herb gardening. Las Vegas and Phoenix deserts have two growing seasons, Eide explains. You can put herbs out in fall, once summer’s heat has abated, and then again in later winter or early spring, when the threat of freezing temperatures is over. As far as location goes, some herbs thrive in full sun, while others require afternoon shade or dappled light. A good nursery is a font of herbal advice.
Rosemary is one herb that does well in arid climates. “They plant rosemary by freeways,” says Eide, “so you know it’s very hardy in this climate.” Basil, chives, parsley, mint, thyme, oregano and other common herbs also do well in the desert–but, as Eide points out–they often behave as annuals, dying out once it’s too hot or too cold.
Fennel, dill and cilantro can be tricky, she says, more adapted to cooler weather and tend to bolt, or set seeds quickly. “Borage and comfrey also don’t do well in the desert,” says Eide, “but there are always exceptions. Some people have just the right microclimate and they thrive.”
Eide’s personal favorites? “I like desert oregano. It’s native to the Sonoran and Chihuahuan deserts, but it has sharper scent and taste than other oreganos.”
Want to learn more? The Springs Preserve offers gardening classes, tours and a new teaching garden, where you can learn about growing–anything–from the ground up.