The air feels like an oven this time of year in the Bard valley. The temperature has reached over 110F every day for weeks now – some days coming close to 120F – forcing most residents of the agricultural valley, nestled at the intersection of the Arizona, California and Mexican borders, inside. But the date palms at Sun Garden Farms love it.
As a heatwave rolls across the south-west, leaving cities like Phoenix and Death Valley national park experiencing record-setting temperatures, crops are wilting in the extreme heat – leaving many farmers worried their yields will fall come harvest. But here, the heat, however extreme it feels, is welcomed. Dates are built for desert climates and the temperature will help the fruits ripen as their sugars develop.
Hundreds of date palms fill Sun Garden Farms’ nearly 200-acre property. But each palm, and every other one of the thousands of date palms grown across the Bard valley region, are descendants of just one palm that was growing in Morocco nearly a hundred years ago. When the harvest begins next month, the grandchildren of that Moroccan date palm will feed date lovers across the world – even as other crops struggle to survive rising temperatures.
In the south-westernmost corner of Arizona, just 3 miles from California and 10 miles from Mexico, the town of Yuma is one of North America’s most important agricultural hubs. Nicknamed “The Winter Salad Bowl”, the Yuma area supplies the United States and Canada with 90% of its winter, leafy vegetables – even in the coldest months of winter, temperatures don’t generally fall below 50F.
Although most of Yuma’s agricultural activity occurs in the wintertime, it’s particularly well-known for one summer crop: the Medjool date, which is also grown in neighboring parts of California and Mexico. Nearly 100 years after it first arrived in the United States, the Medjool date is weathering the extreme heat better than many other crops – largely because it was imported in the early 1900s because of its ability to thrive in a hot, dry climate.
“They do well because that’s what they like: hot or dry weather, especially in the fruiting season,” said Dennis V Johnson, author of Imported and American Varieties of Dates in the United States. “What they really require is about four months of very low rainfall, low humidity and high temperatures.”
Juan Guzman, senior vice-president of operations at the Yuma-based date company Natural Delights, agrees: “The old adage is that Medjool dates require 100 days over 100 degrees to thrive.”
Date palms have been grown in the Americas since at least the 1700s, when Spanish missionaries began settling in parts of modern-day California and Arizona. But the Medjool date variety did not arrive until much later, after the newly established US Department of Agriculture began hiring “agricultural explorers” to travel the world to collect new plants.
One of those first explorers was botanist Walter T Swingle, who traveled to Morocco in 1927 to study a fungal disease that had begun infecting date palms there. Although agricultural explorers had imported dates from Algeria, Tunisia, Egypt and Iraq as early as 1890, Swingle was captivated by the Medjool dates he found in Morocco – they were nicknamed “the fruit of kings” because they were once only eaten by royalty.
After taking soil and air temperatures, and determining that the Medjool date might successfully be grown in the American south-west – a region then nicknamed “the Sahara of the United States” – Swingle purchased 11 offshoots from a single female date palm. But before these Medjool dates could be grown as crops in the US, they had to be quarantined to make sure the fungus that had infected Morocco’s Medjools wouldn’t spread. For the next nine years, the 11 palms were quarantined in the Nevada desert. In 1936, the palms were finally released – nine had survived, two dug up by a caretaker’s dog – and replanted in Indio, California, where the USDA was already growing a variety of dates, including the popular Deglet Noor variety, which Swingle had brought home from Algeria in 1900.
In the 1940s, the USDA began distributing those nine Medjool date palms to growers.
“Six of those were planted in Bard valley at the intersection of California, Arizona, and Mexico along the Colorado River,” David Baxter, director of marketing at Natural Delights, said in an email. “Medjool dates demand a very specific set of growing conditions where high heat, low humidity and plentiful water meet, and Bard valley is the most ideal location in the United States.” Alongside the arid climate, the Bard valley also has access to deep aquifers.
All six of those palms, as it happened, ended up at Sun Garden Farms, where businessman and lawyer Stephen Philip Shadle opened a date grove. By the 1990s, Shadle and several other date growers in the region would come together to form the Bard Valley Date Growers Association.
Although there are about 3,000 varieties of dates grown worldwide, Medjools are one of the most popular – in part because of the advocacy of growers’ groups and in part because Medjools are larger, softer and sweeter than many other varieties. Like other dates, they’re also good for you.
“Medjool dates are a healthy option any time of year thanks to their potassium, magnesium and fiber content in addition to the fact that they are low on the glycemic index,” said Baxter.
While this year’s extreme heat has actually been beneficial to the date crop, there are other ways that climate crisis could affect their growth.
“The thing to worry about would be if there are some climatic changes that bring about more rainfall than normal,” said Johnson.
Heat itself isn’t enough for a successful date crop: it’s key that it continues being dry heat.
Today, two of the original date palms that Swingle imported from Morocco still stand – at Sun Garden Farms. Towering nearly 100ft in the sky, the two palms look over the Bard valley, where over the past 70 years thousands of their offspring have grown.
