You can turn seasons (not the EP, but spring, summer, etc.) on or off in the Options menu, as well as set the length of each. Look for the tab with the leaf on it, and there's a check mark for each season and then a spot for number of days. So if you want a lot of farming, turn off the non-summer seasons, or turn off winter and fall and make spring very short. You can also turn off precipitation types; my Isla Paradiso save has no snow, for instance, although it may get rain hail and/or fog in the appropriate circumstances.
