There are a few terms. A horticulturist or a Master Gardener would be the academic equivalents of specialization in Gardening. They tend to be passionate plant, soil, fungus, biology science nerds, of which I feel is part of my Specialized Gardener Identity.
I was once The Specialization Project Manager for a large commercial landscaping company once, the best and worst of corporate large scale landscape companies. As Specialization Project Manager, I was in charge of all the projects the other mangers didn’t know what to do with, as well as seasonal décor design and installation, and pruning for over 200 properties. I had to know how to do a lot of different things and often was in the field with my crew making sure we got the work done.
Often though, those who go by the academic titles are more interested in the heady side of gardening and are not as efficient at the manual labor part of the business. You must be both athletic in your physical practice of the skill as much as you are in your head when it comes to the whole picture and the tiny details of the science involved in making a design successful. Adding artistic design to the list of The Specialized Gardener makes them a triple whammy of a hire.
Most Landscape Designers, as previously mentioned in my other blog entry on landscapers versus gardeners, do not learn the science or do the manual labor aspect of creating a landscape or garden. They are taught how to make a pretty picture, perhaps have a botany class and perhaps a basic understanding of material based on previous uses limited to input output of a design. If you take a designer and have them keep their design alive, you may run into trouble. If they do not have experience with the other variables associated with the sciences integrated into the garden designs survival and thrivability, they would see that a pretty picture evolves over time and requires constant input to maintain the idyllic image they created.
A professional who has a wide range of knowledge is someone who truly specializes in gardening, no matter what they decide to identify themselves as. Get to know your professionals to know how to build the best relationships for your garden needs!