The qualifications needed to get a garden job depend on the type of employer. For example, at a nursery, managerial positions usually require a high school diploma or GED certificate and some previous experience in a nursery or garden setting. Retail workers usually only need a high school diploma, although it is common for high schoolers to work at a nursery after school or during the summer. If you work freelance, you may just need reliable transportation and your own gardening equipment. Some gardening companies prefer workers who have a high school diploma or certifications to manage responsibilities like fertilizer and pesticide application. Good interpersonal skills are important for any of these positions.