A full time college student only spends 15 to 18 hrs in class for 15 weeks in the fall and 15 spring.
I do not know of a landscaper starting out with 40 hours a week of steady work.
So I see no problem doing both.
As to the teacher that got hammered during the fall cleanups you hire help when you get backed up.
I would suggest a Horticulture, Landscape Design program at a local 2 year college.