Deep-layer soil desiccation (DSD) can restrict the sustainability of deep-rooted plantations in water-limited areas. Thus, we explored the extreme effects of DSD based on mass data published and measured on the Loess Plateau and found that the permanent wilting point is a reliable indicator of the moisture limitation of DSD, regardless of tree species, with the corresponding maximum root water uptake depth varying among climatic zones. These dimensions increased the risk of planted trees' death.