Chia seeds come from Salvia hispanica, a flowering plant in the mint family that is native to Mexico and Guatemala. The plant was first cultivated in the Nahuatl-speaking regions of central Mexico several thousand years ago, and it remains one of the oldest continuously used food crops in the Americas. Today, most of the world’s chia is grown in South America, with Paraguay, Bolivia, and Argentina accounting for nearly 80% of global production.
The Chia Plant
Salvia hispanica is an annual herb that can grow up to about five feet nine inches tall under good conditions, though wild plants tend to stay shorter, often under three feet. It has broad, oval leaves with serrated edges arranged in opposite pairs along the stem. When the plant flowers, it sends up tall spikes from the tip of each branch, packed with dozens of small blue to purple (sometimes white) flowers. After pollination, each flower produces tiny seeds, roughly 1 to 2 millimeters across. Those are the chia seeds you find in stores. They come in black and white varieties, but there is no difference in nutritional content between the two colors.
Because chia belongs to the mint family (Lamiaceae), it shares traits with herbs like basil and rosemary: square stems, opposite leaves, and lipped flowers. But unlike most kitchen herbs, chia is grown primarily for its seeds rather than its leaves.
Ancient Origins in Mesoamerica
Chia was a staple food in Mesoamerica as early as 3500 B.C. The Aztecs and Maya both cultivated it extensively, and in some communities chia even surpassed maize as the most important part of the local diet. The word “chia” itself comes from the Nahuatl word chian, meaning “oily.” In the Mayan language, the adopted word grew to mean “something that makes you strong.”
For the Aztecs, chia was far more than food. The seeds were pressed for oil used as a skin moisturizer and mixed into face and body paints. They served a role in religious ceremonies, offered as gifts to the gods. And they functioned almost like currency: Aztec records show that 21 of the 38 provincial states paid chia seeds as annual tribute to their rulers. The capital city of Tenochtitlan received a minimum of 4,410 tons of chia per year from conquered nations, alongside similar quantities of maize, beans, and amaranth.
Indigenous tribes in what is now the southwestern United States also consumed chia, though they typically used a related species called Salvia columbariae, sometimes known as golden sage or desert sage. Native groups including the Paiute and Chukchansi Yokuts each had their own names for it. This desert-adapted relative thrives in arid conditions, unlike the cultivated chia that needs richer soil and more water.
One of the most famous traditional uses comes from the Tarahumara people of northern Mexico, renowned long-distance runners who drank a mix of chia seeds, lemon, and water called iskiate before their runs.
Where Chia Grows Today
Paraguay is now the world’s top producer and exporter of chia seeds by a wide margin. In 2024, it exported nearly 70,000 tons, a 41% increase over the previous year. Bolivia ranks second with roughly 12,000 tons of annual output, followed by Argentina. Together, these three South American countries supply the vast majority of the global market, which demands an estimated 80,000 to 100,000 tons of chia seeds per year.
Mexico and Guatemala, where chia originated, still grow it but are no longer dominant producers. The crop has also spread to Australia, parts of Africa, India, and even experimental plots in the United States. In Kentucky, for example, chia is planted in May or June and harvested in October using standard grain combines fitted with fine screens.
Why Climate Limits Where Chia Can Grow
Chia is a tropical plant with specific needs that restrict where it thrives commercially. It grows best in temperatures between about 16 and 26°C (roughly 60 to 79°F), tolerates a range of 11 to 36°C, and cannot survive frost. It needs well-irrigated, fertile soil and moderate rainfall of 500 to 1,000 millimeters during the growing season.
The biggest limiting factor is day length. Chia is a short-day plant, meaning it only flowers and produces seeds when daylight drops below about 12 to 12.5 hours. This is why it naturally evolved near the tropics, where days are relatively short and consistent year-round. When planted at higher latitudes with long summer days, chia keeps growing leaves and stems but delays or skips flowering entirely. That extra vegetative growth comes at the expense of seed production, which is the whole point of commercial cultivation. Breeders have been working on varieties less sensitive to day length so the crop can expand to new regions, but most commercial chia still comes from subtropical zones where the photoperiod cooperates naturally.
From Field to Store Shelf
Chia is typically planted at the start of the warm season, grows for four to five months, and is harvested once the flower spikes have dried and the seeds are mature. Commercial farms use mechanical combines, the same machines used for grain crops, with smaller screens to catch the tiny seeds. After harvest, the seeds are cleaned to remove plant debris, then dried if needed to bring moisture content low enough for storage.
Because chia seeds have a naturally high oil content (rich in omega-3 fatty acids), that oil composition actually helps the seeds perform well across a range of temperatures. The high proportion of polyunsaturated fats keeps cell membranes flexible, which is one reason chia seeds germinate reliably even in cooler conditions around 10°C, after a brief lag period of about four days. This resilience makes the crop relatively forgiving for farmers, as long as the day-length and frost requirements are met.