Most colleges and universities offer courses in botany and/or landscaping, both vital to the trade. Acquire certifications for one or both, and practice cultivating, preparing, planting, transplanting, and growing.
I would go online and see what you can get for books and informational sources im sure some local libraries and colleges would be able to give you information
The best way to start is to study subjects that deal with gardening. Landscaping is the first that I would start with. Also there is Hordiculture and Agriculture. Make a study of these to become a professional gardener. There might be classes you can take to get certified.
