Landscaper all work the same way! We have the same

problems. However, it's common sense to pay them by 40/30/30 ratio. i.e., downpayment 40%, at middle point 30%, when finish the jon 30%.
If you pre-pay them in advance, you put youself in a really bad situation. Even if you sue him, the best case is you just get your money back (if you are lucky). You waste all you energy and time and your life totally messed up.
I don't know how can help you but good luck!