Cleaves the polyglutamate sidechains of folate polyglutamates in the vacuole. Is important for polyglutamyl tail length determination before vacuolar exit. Plays a role in folate stability and intracellular folate content. (6S)-5,6,7,8-tetrahydrofolyl-(gamma-L-Glu)(n) + (n-1) H2O = (6S)-5,6,7,8-tetrahydrofolate + (n-1) L-glutamate Extracellular or cell-wall bound. Highly expressed in roots and at lower levels in leaves, stems and siliques. No visible phenotype under normal growth conditions. Belongs to the peptidase C26 family.