Both. I took schooling for horticulture right out of highschool. The courses in my area were very limited at the time so I had to take from 4 colleges across the country via distance Ed.
After that I took a degree in business from our local university. Major in finance, minor in economics.
I worked under a journeyman landscaper for 5 years then bought his business name when he threw in the towel for $1500. Came with a wheel barrow and 2 shovels.
Since, I have become a certified Allan block wall installer, bark an factory trained technician, and icpi certified. Along with every foreman in the company.
I taught landscape design at a local college for 2 years as well, but didn't renew the contract this year. With the amount of time I was prepping and doing other tasks outside of class, it was interfering with work. The wage worked out to about $15/hr so I considered it a donation.