Horticulture is the branch of agriculture that deals with the art, science and business of plant cultivation. This includes plants that are edible and ornamental. It also includes conservation of plants, restoration, landscape, design and construction.
Since agriculture is a basic need for humans, there is always a lot of scope in this field of study. With the advent of technology and developments that comes with it, there has been a wide variety of job opportunities in both public and private enterprises.
Career options are:

Production and sales
Marketing
Research and Development
Teaching
Pest Management

So you can choose to go in this field if interested in the above job profile and scope.

Good luck!