*k(w)ert- is glossed in LIV as 'binden'. It is only found in Ved. cṛtáti 'he binds'.
*gʰerdʰ- is glossed 'umschließen, umgürten'. It is found in ON as gyrða 'to gird'. Also often found denominaly like in Dutch gordel 'girdle' from *gʰrdʰ-lo-. Also related is Skt. gṛha- 'house' and OCS gradъ 'city, garden'.
Both roots are mainly found in Ø-grade. But in gothic we find gairda 'girdle' which actually points to an *e-grade.