Hello Cangarden
If you mean expense category ,are you looking to differentiate between on reports between the expenses to the gardeners or just have one expense category for all?
As we are not trained accountants we can not give advise on which category to use,there is not a specific one.However you can go to accounting>chart of accounts>new>expenses and each detail type has an explanation of when to use it,it is a case of selecting the most relevant one.You can always then confirm with an accountant they are happy with what you select.
Emma