[Objectives] We planted and screened suitable Forsythia plants for growth on a typical red soil in an eroded red-soil region of South China in order to provide a scientific basis for the scaled expansion and popularization of Forsythia resources.[Methods] F. suspense (P₁), F. viridissima (P₂), and F. suspensa var. sieboldii (P₃) were used as test materials in this study. Three moisture gradients (-5, -20, and -35 kPa) were designed using artificial water control experiment on three types of red soil that were developed from granite (S₁), red sandstone (S₂), and Quaternary red clay (S₃) parent materials. We then analyzed the effects of each type of red soil and moisture condition on the growth of the three Forsythia species.[Results] ① Under the three moisture gradients, the lowest irrigation time and lowest volume of irrigation water for each Forsythia species were on the S₁ soil. The irrigation volume and irrigation time of the S₃ soil were higher than those of the S₂ soil at -20 and -35 kPa, while they were the same at -5 kPa. ② Soil moisture and soil type significantly affected the growth and development of Forsythia plants on the typical red soils; however, no significant difference was observed among the plant species. The interactions between soil type and soil moisture, as well as soil type and Forsythia species had significant effects on all growth indices, and the interaction between soil moisture and Forsythia species had a significant effect on all growth indices excluding branch length. Among the three Forsythia species, under high soil moisture conditions (-5 kPa), the best growth of P₁ and P₂ occurred in the S₂ soil, while P₃ grew best in the S₃ soil. However, with a decreased moisture content (-20 and -35 kPa), all three Forsythia plants grew best in the S₃ soil.[Conclusion] In South China, it is feasible to plant the three Forsythia species under high moisture conditions in red soil that has either red sandstone or Quaternary red clay as the parent material and a soil matrix potential of ≥ -35 kPa.