Most are easy to grow and offer years of pleasure for your investment. You will need to look at perennials as a trade off. Instead of blooming all season like an annual, their bloom time is shorter so they can come back to do it again. Annuals and perennials compliment each other, so use them together. Technically, a perennial is an herbaceous plant that lives three or more years.
Herbaceous plants die back to the ground each winter.
The life span of various perennials can range from just a few years to decades. Perennials are probably the most useful, versatile plants around. Use them in beds, borders, with evergreens, in containers, in cutting gardens or anywhere you need them. There are perennials suitable for almost every site, from hot and dry to damp and shady. The site itself is the most important element in choosing the right perennials.