In a corner of the Los Angeles County Arboretum, there’s a small, offsite patch of land where olives, grapes, lemons, a curry bush, mulberries, apples, figs, and pomegranates grow. The land is self-sufficient and does not require heavy maintenance, lawn mowers, or weekly watering sessions. It was originally designated as an experimental garden, but proved to be such a success that the Arboretum gave the green light this spring to Crescent Farm, a large-scale farming project located in a more accessible area in the park. There you can find wildflowers, rainbow corn, and passionfruit growing, just half a year after they put in the first planters.
All of this is impressive given the context in which everything grows: with very little added water and in the worst drought in California history. The gardens subsist off of rainwater—even though there’s been so little of it.
This isn’t an elaborate magic trick or a ploy. Both the Crescent Farm and the offsite garden in the Arboretum are food forests cleverly engineered to harvest rainwater and store the water in the ground. Through the use of swales, lasagna mulching (a method of layering compost that leaves the ground is porous), permeable surfaces, and curb cuts (cutting into a curb so that rainwater from the street is routed into the garden instead of to the gutter), they are amazing demonstrations of what is possible during a drought.
Water is tight in California, to say the least. Los Angeles saw just 9.65 inches of rain this year, with much of its water now coming from the Colorado River, the Delta in northern California. and the eastern Sierra Nevada Mountains.
“Take an average sprinkler. Fifty percent of the water that shoots out of that is evaporated,” Leigh Adams, the Arboretum’s lead horticulturist at the Crescent Farm, says. She pauses for effect. “What are we doing?”
The eccentric, purple-haired Adams has been gardening her entire life, but it wasn’t until she started planting at her weekend property in the Mojave Desert that she realized how much could be grown in a place of apparent scarcity.
The story goes like this: Decades ago, a fire had broken out in the desert and burned nearly all the vegetation. It was devastating to Adams, so she collected the broken sticks and burnt logs for remembrance.
“I arranged the burnt sticks, rocks, and broken tree branches around the new shrubs in the garden, just sort of as an homage to what had been there,” she says.
Years later, when she was flying over the property with her friend on a private airplane, she was shocked to see that her land was an oasis of green that popped out dramatically against the blackened, burnt lands of her neighbors.
“People’s trees didn’t come back but mine did. I didn’t understand it at the time. I just arranged those burnt up logs there just to deal with the grief. Today I understand that the physics behind that is thermal mass and condensation,” she says.
Unbeknownst to her at the time, Adams had created one of the elements of a composting technique called hugelkulter. Essentially, piles of logs and sticks act like a sponges; rainwater gets stored in them and then released during drier times to anything planted atop them, mimicking the natural process of decomposition that occurs on forest floors, which nourishes the plants.
Adams decided to experiment with this technique at the Crescent. Under the logs and throughout the farm is a network of naturally occurring fungal mycelium, which links the roots of different plants to help them access water and nutrients. In exchange, the plants provide the fungus with carbohydrates. It’s a symbiotic relationship called mycorrhiza.
“Mycorrhiza spreads water out horizontally,” Adams says. “Every year, the fungus increases its water intake.”
To store water vertically, she built swales at the farm—long, shallow depressions designed to collect and redirect water to plants. That water is effectively stored in the ground through lasagna mulch, which is soil made from layering yard and food waste. The waste breaks down, giving way to nutrient-rich earth and, most importantly, a porous environment so that water is retained. Additionally, permeable walkways allow rainwater to seep into the ground instead of being routed to the gutter. All of these techniques fall under an umbrella term Adams calls “water harvesting.”
“We’ve known for 40 years that we’ve been depleting the San Joaquin Valley Aquifer,” she says, referencing an important water source for California. “Yet when it does rain, all the rainfall water drains into the ocean. If we harvested that water, our aquifer wouldn’t be dropping at such a steep rate.”
The Arboretum is located in an ideal place for water harvesting. Located in the city of the Arcadia, the area used to be the Arcadia Wash. When it rained, water would naturally flow to the town and seep into the soil. However, because of concrete pavements, today most of that water is now routed to gutters and straight into the ocean. To redirect that water, Adams had curb cuts installed at the offsite garden in the Arboretum and used bricks to reroute water runoff from the street into the land. It’s a simple technique, but one that took a lot of convincing to get approved. Adams wanted several curb cuts; the city only allowed her three.
Measures like these may seem like common sense in a drought, but in the suburbs that neighbor the Arboretum, curb cuts are virtually unheard of and most of the houses still have luscious green lawns.
“If you are in England or on the East Coast, then fine—have as many lawns as you want,” Adams says. “But lawns don’t belong here. Think about it. We can have gardens that are curvaceous like a woman and can grow food with less water than we are using now. But we don’t.”
She shows me photographs of her own garden. Like the Crescent Farm, it is also devoid of grass. But what it lacks in filler it makes up for in fruit trees. It’s layered with mounds and small hills, harnessing the power of gravity so that water can be properly routed. Adam’s average water bill is a mete $45 a month.
“We can be creating habitats, instead of these dead patches of grass that people have with no life,” she says. “The water that you are pouring on your grass can go into your trees. You can grow food and shade your home.” Adams stresses the importance of gardening with native plants because they help attract a bevy of native pollinators like hummingbirds, bees, and butterflies.
And it’s not just food that can be created in a drought. At the Arboretum, Adams shows me the beginnings of a basket she weaved using dried twigs. There is also a rocket oven that she built entirely with the soil in the garden.
“The oven can fire up to 450 degrees in 20 to 25 minutes with just six pieces of firewood,” she says. “You can bake pizza and breads in there.”
Drawing from what she learned in the Mojave, Adams’ entire philosophy is centered around creating value out of scarcity. Food, she has proven, can grow even in drought-ravaged land if the garden is engineered properly.
Currently, she is campaigning for the Arboretum to install a water-harvesting parking lot. She wants to apply some of the same philosophies in the farm to the lot, create permeable surfaces so that precious rainwater is not wasted. Though she has the support of her colleagues, she notes that it’s an uphill battle trying to convince city planners to agree to the rainwater collection plans.
“All of the water is running off,” she says. “It doesn’t make sense. We are so brainwashed.”
Every day this week, MUNCHIES is exploring the future of food on planet Earth, from lab-grown meat and biohacking to GMOs and the precarious state of our oceans. Find out more here.