* The specific institution: Different colleges and universities have different credit requirements for graduation, even within the same state or country.
* The degree type: An Associate's degree in horticulture will require far fewer credits than a Bachelor's degree, and a Master's degree will require even more. Some institutions also offer certificates in specific areas of horticulture.
* Specializations: A student specializing in landscape design might have different required coursework (and therefore credits) than a student focusing on plant breeding or plant pathology.
To find the specific credit requirement, you need to check the catalog or website of the particular college or university offering the horticulture degree program you are interested in.