Generally, you want to consider the time and maintenance involved, and to gauge this, Apartment Therapy suggests asking the following questions:
How hardy are the perennial plants to your climate zone? Are they short-lived and will they need to be replaced in a couple of years?
How often will they need to be watered, and are you able to install an automatic irrigation system if needed?
Do they require regular pruning, deadheading, or trellising throughout the season?
Are they susceptible to pests or diseases, and if so, are there other varieties bred to combat these problems?
Ideally, your answers will give you a clear idea of the time and maintenance required. For more tips for picking the right plant, head to their full post below.
The Fun Part: Choosing the Right Plants for Your Space and Lifestyle [Apartment Therapy]