In 2024, Nevada filled 1.8 million solar panels across the Mojave Desert; a rare milkvetch plant growing inside the farm started to produce 8 times more flowers and 10 times more fruit than plants outside

A rare desert plant unexpectedly performed better after a huge solar project was built across its Mojave habitat. At Nevada's Gemini Solar Project, threecorner milkvetch plants growing inside the 20-square-kilometre facility produced roughly eight times more flowers and ten times more fruit than plants at an undisturbed site outside the project.

The result surprised researchers because utility-scale solar development can disturb desert soils and vegetation. But Gemini used construction methods designed to minimise that disturbance, leaving areas of vegetation and soil intact. A 2025 peer-reviewed study found that the rare annual persisted inside the facility and, during the year studied, grew larger, reproduced more and reached its fruiting stage nearly three weeks earlier than plants outside.

From 12 plants to 93

The threecorner milkvetch, Astragalus geyeri var. triquetrus, is a rare annual plant belonging to the pea family. Before construction, a 2018 survey recorded just 12 plants at six locations within the area that would become part of the Gemini project.


Construction began in 2022 and ended in 2023. When researchers returned in 2024, they found 93 threecorner milkvetch plants inside the solar facility.

That did not mean every part of the solar farm was equally suitable. About 94% of the plants recorded inside Gemini were growing in the interspaces between panel rows. Only one plant was recorded directly beneath a panel, suggesting that the plant benefited from the conditions created around the panels rather than from deep shade itself.

The plants started reproducing earlier

The difference was not limited to the number of plants.

Researchers monitored plants inside Gemini and compared them with a population on nearby BLM-managed land outside the facility. Plants inside the solar project were significantly larger and showed earlier phenology.

Fruiting occurred about 2.7 weeks earlier at Gemini. By the end of the growing season, plants inside the facility had produced about eight times as many flowers and ten times as much fruit as those outside.

Survival, however, was not significantly different between the two populations. That distinction matters because the study was measuring growth and reproduction as well as whether individual plants survived.

Why the panels may have helped

The likely explanation is not that the plants simply enjoyed being shaded.

A separate 2026 study of Gemini's microclimate found that the solar installation created different patterns of temperature, wind and soil moisture. The plant study found that soil moisture at several depths remained elevated for longer inside the facility following fall and spring precipitation.

For a desert annual dependent on limited rainfall, keeping moisture in the soil for longer can make a major difference. The researchers suggest that this retained moisture may help explain why the milkvetch plants inside Gemini grew larger and reached reproductive stages earlier.

The panels also alter rainfall distribution. Water falling on the panels can run off towards the ground near their edges, while the structures can change wind and solar exposure. But the milkvetch appeared to favour the spaces between the rows, where it could receive substantial sunlight while benefiting from the altered microclimate.

Construction method may have mattered

Gemini was not built using the most disruptive approach across the entire site.

The project used methods including "drive and crush" and overland travel to reduce disturbance to vegetation, soil and hydrology. The researchers say these methods allowed a viable threecorner milkvetch seed bank to persist through construction.

That may have been crucial. The plants found in 2024 did not necessarily represent new seeds arriving from somewhere else. The researchers concluded that the construction approach allowed the existing seed bank to survive and produce plants after the solar project was built.

However, scientists do not yet know how long threecorner milkvetch seeds can remain viable in the soil. The study confirmed that seeds collected from the Gemini population were viable, but the researchers say the species' seed-bank longevity remains unknown.

An unexpected result, with a major caveat

The findings do not mean solar farms are automatically beneficial to desert plants.

The researchers describe their biological results as coming from a one-year study conducted during a favourable rainfall year. They also found very low plant emergence directly beneath panels and along their driplines, which could represent a loss of suitable habitat if the pattern persists over time.

The study therefore points to a more complicated relationship between solar infrastructure and desert vegetation. Panel spacing, construction methods, rainfall, soil conditions and the biology of individual species can all influence what happens after a solar project is built.

At Gemini, the result was particularly striking: a rare plant that had only 12 recorded individuals before construction was found 93 times? No, 93 individuals inside the facility in 2024, with those plants producing dramatically more flowers and fruit than their counterparts outside.

The researchers say the findings can help land managers consider ways to reduce ecological impacts as demand for utility-scale solar energy grows.