you can rent a mini excavator, if you are needing to go through roots and rocks within the ground. mini excavator = backhoe and nothing else exception a little push blade on front. to push dirt back into the trench.
or you can rent a trenching machine (that has a chain saw looking blade) if you have a good amount of trench, you can get self propelled walk behinds, to bigger machines that you ride on.
possibly rent a ditch witch, that has a small backhoe on one end, and then a chain saw looking blade on other end. plus blade on one of the ends to help push dirt back into the trench.
check some rental places, even those a couple hours away, prices can range big time. and check for discounts for 2 day, 3 day, weekly rates. you might also try some local tractor dealers. they may rent some stuff out as well.
if you do not have a trailer, but have a truck you can tow with, you can normally rent a trailer at same time getting a rental machine. (double check though not always have an extra trailer available) or have machine delivered.