Forgotten indigenous crops could help solve modern climate issues

Children learn about the “three sisters” – corn, beans, and squash – growing together, but that’s only part of the story. Long before Europeans set foot on the continent, Indigenous farmers in eastern North America cultivated a far more diverse range of crops.

Goosefoot, sumpweed, and knotweed once thrived alongside squash and sunflowers. These crops vanished from fields and memory, leaving behind only seeds and traces in archaeological records.

Natalie Mueller, an archaeologist at Washington University in St. Louis, studies these “sleeping” crops. She didn’t come up with that term. It came from members of the St. Louis Native American Women’s Care Circle during a community event.

“They pointed out that ‘lost crops’ had kind of an Indiana Jones vibe and evoked this colonial myth that Indigenous cultures and people were extinct,” Mueller said. The crops aren’t lost. They’re waiting.

How Indigenous farmers managed crops

Before maize dominated the fields, Indigenous farmers managed a complex agricultural system known as the Eastern Agricultural Complex (EAC).

The EAC included crops that most people now call weeds – maygrass, little barley, and knotweed. In the past, they weren’t just weeds. They were food that was cultivated, harvested, and stored.

Floodplains played a key role in this system. Rich, wet soils created ideal conditions for these plants. Mueller’s research explores how Indigenous farmers gradually moved these crops from floodplains to uplands.

The shift changed the crops themselves. Seeds that once sprouted unpredictably started to germinate more uniformly. Over generations, seeds became larger and more productive.

Today, remnants of these crops linger in the landscape. They grow in ditches and along roadsides, unnoticed, while modern agriculture focuses on corn and soy. Mueller’s work urges a closer look. These “sleeping” crops could provide crucial food security in a changing climate.

The evolution of domestication

Mueller’s experiments trace the evolutionary journey of these crops. Her lab grows goosefoot and knotweed under controlled conditions, replicating ancient farming techniques. The goal? To see how these crops might have evolved under human care.

Seeds found in archaeological sites often show signs of selection. Domesticated knotweed seeds, for instance, are larger than their wild counterparts.

The seeds germinate faster too. Mueller suggests that this transformation wasn’t accidental. Indigenous farmers likely selected seeds with minimal dormancy, favoring those that sprouted quickly in stable, managed fields.

But not all crops evolved the same way. Sumpweed, for instance, remained more variable, producing seeds with mixed dormancy traits. This variability may have helped it survive in unpredictable floodplain habitats.

Mueller’s studies suggest that by moving these crops to uplands, Indigenous farmers inadvertently reduced their genetic plasticity. The crops became more uniform, more predictable, and more dependent on human intervention.

Indigenous crops, steady food supply

Eastern North America wasn’t a monoculture. Indigenous farmers cultivated multiple crops, each serving a unique purpose. Maygrass ripened in spring, goosefoot in summer, knotweed in fall. The result was a continuous food supply, with different crops reaching maturity at different times.

Mueller’s research uncovers evidence of landraces – distinct varieties of the same crop, each adapted to specific microenvironments.

In some sites, farmers grew multiple types of knotweed, each with slightly different traits. One type thrived in wetter soils, another in drier uplands. This diversity wasn’t accidental. It was a form of agricultural insurance, a way to hedge bets against changing conditions.

Today, industrial agriculture emphasizes uniformity. Fields stretch for miles, each planted with a single crop. But in the past, diversity was the norm. Mueller’s work calls attention to what we’ve lost – and what we could regain by reintroducing these sleeping crops.

Beyond the crop field

Indigenous farmers didn’t just plant seeds. They shaped entire landscapes. They managed forests with controlled burns, encouraging the growth of nut-bearing trees like oak and hickory. They cleared patches of prairie to attract bison, whose grazing helped maintain open habitats.

In wetlands, they cultivated aquatic crops like American lotus. These flood-adapted plants thrived in waterlogged soils, providing food in areas unsuitable for other crops.

Mueller’s work suggests that ancient farmers practiced a form of agroecology, managing diverse habitats to maximize food production without depleting resources.

Mueller points to Cahokia, a sprawling pre-Columbian city near present-day St. Louis. At Cahokia, farmers dug borrow pits to extract soil for building mounds. These pits filled with water, creating artificial wetlands.

Archaeologists have found seeds of sumpweed and little barley in these wetlands, suggesting that farmers cultivated them intentionally. These wetland crops might have helped sustain Cahokia’s population during periods of drought or flood.

Reintroducing sleeping crops

Mueller’s lab at Washington University has taken small but significant steps toward reviving these crops. They maintain a seed bank, distributing seeds of sleeping crop progenitors to educational institutions and Indigenous farmers.

The lab also provides growing guides, encouraging people to experiment with these ancient crops. But reawakening these crops isn’t just about planting seeds. It’s about restoring relationships.

“This was also the first of many times that I have spoken to Indigenous growers and seed keepers who consider seeds to be living beings that are sleeping or waiting for their human kin to pick up their side of the relationship and plant them,” Mueller said.

Mueller’s work aligns with a broader Indigenous food sovereignty movement. In eastern North America, descendants of the original farmers are reclaiming agricultural knowledge, replanting ancient crops, and restoring land management practices.

This movement challenges the idea that Indigenous agriculture vanished when European settlers arrived. It didn’t vanish. It just went to sleep.

Return of floodplain crops

Floods are becoming more frequent and severe in the Midwest. While the region’s dominant crops like corn and soy struggle in waterlogged soils, sleeping crops evolved to handle such conditions. Sumpweed, knotweed, and goosefoot thrived in floodplains, producing food where other crops would fail.

Mueller suggests that these crops could offer a low-input alternative to conventional agriculture. Rather than fighting floods with levees and drainage systems, farmers could adapt by planting crops designed for wet soils.

“Cultivating wetland or floodplain-adapted crops instead of industrial corn and soy could be a low-input way out of this trap,” Mueller said.

Experiments in Mueller’s lab show that when grown together, certain crops – like knotweed and goosefoot – boost each other’s productivity. This synergy mimics the “three sisters” system, but with less familiar crops.

The potential for these crops to thrive in marginal lands could provide a critical buffer against climate-related crop failures.

The future of indigenous agriculture

Reawakening sleeping crops isn’t just about food. It’s about identity, resilience, and reconnecting with the land. It’s about challenging the narrative that Indigenous agriculture vanished, acknowledging that it was forcibly suppressed and systematically erased.

Mueller’s research offers a blueprint for restoring lost agricultural systems in eastern North America. But the real work lies in building bridges between researchers, farmers, and Indigenous communities.

It’s a collaborative effort, one that requires more than seeds and soil. It requires respect, recognition, and the willingness to listen.

The sleeping crops are still here. They’re waiting. The question is: Are we ready to wake them up?.

The study is published in the journal Philosophical Transactions of the Royal Society B Biological Sciences.

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