[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.