<i>Thinopyrum intermedium</i> showed a slower establishment phase compared to winter wheat in a controlled environment

Abstract Thinopyrum intermedium is currently proposed as a perennial grain crop benefiting from raising interest through its environmental performances. As a new crop, little attention was paid to the understanding of the eco‐physiological regulations of its growth cycle. We conducted an experiment in growth chambers to evaluate the aboveground and belowground development of Th. intermedium in comparison to annual wheat during the first days of growth after sowing. The dynamic of growth was faster for wheat, in line with a strategy of rapid acquisition of resources and a quicker colonization of its environment compared to Th. intermedium . In contrast, the latter had a preferential investment in roots that could reflect an adaptation from nutrient‐poor environments to prioritize soil resource acquisition. These insights highlighted a slow establishment phase for this new crop, which may lead to difficulties during the field establishment, such as weed competition, but could enable it to withstand stressful conditions in terms of soil resources once well established.