It can be tough living in a temperate climate. Although generally considered a place where "moderate" temperatures dominate, this can often times mean hot summers and cold winters. This fluctuating set of temperatures can cause for some strange gardening tics. In these climates, perennial plants are your best friends. Perennial plants are any plant that can live more than 2 years, which means that they're tough, long lasting and, many times, very beautiful to look at.