"you give God one tenth of your mint and rue and other herbs from your garden." Jesus was giving an example of how extreme the Pharisees were in giving a tenth of their income.
These are herbs. People put just a little bit of these leaves into their food to give it flavor. If people do not know what mint and rue are, you can use the name of herbs they know or a general expression such as "herbs." (See: [[rc://en/ta/man/translate/translate-unknown]])
"without failing" emphasizes that this should always be done. This can be stated in positive form. Alternate translation: "and to always do the other good things as well" (See: [[rc://en/ta/man/translate/figs-litotes]])