What makes annual plants "annual" and perennial plants "perennial?" It's all in the life cycle, as I explain below. I also discuss how these colorful characters are used in landscaping.
Botanically speaking, annual plants complete their life cycle in one year:
- You place the seeds from last year's flowers in the ground in spring
- New annual plants sprout from the seeds
- With proper care, during the course of the summer, these produce flowers
- Toward the end of the growing season, annual flowers yield seeds -- signaling to the annual plants that their life cycle is complete
The Difference Between Annual Plants and Perennials
Thus the difference between annual plants and perennials. For perennials usually don't produce flowers their first year (grown from seed) but make up for it by flowering more than 1 year. That is, they have a longer life cycle.
Some plants that are perennials in their native (e.g., tropical) lands are treated as if they weren't in colder regions. Here, one might say that usage trumps botany. E.g., lantana plants are, technically, perennial, but they're treated as annual plants in regions far to the north of their ancestral home -- regions too cold for them to complete their life cycle.
Some folks understand this distinction but still have trouble remembering the terminology. If you can't ever seem to remember which is which, use the following as a mnemonic device:
- The root in both words, "annual" and "perennial" (i.e., per-annual) is the Latin word for "year," annus
- Annual plants are thus those that last but a year in their native climes
- Perennial plants have something extra: that "per" in their name. The per- prefix in Latin intensifies or adds to what comes after it. So perennials live additional years, when compared to annual plants.
How Annuals Are Used in Landscaping
Many gardeners despise annual plants. This fact is somewhat inevitable, as those proud of their gardening knowledge and skills will always be on the lookout for new things to try. They view most annuals as commonplace and trite.
But dirt-common or not, annual plants do have a place in landscaping. They inject long-lasting color into the landscape in places where, otherwise, one would find the dreaded empty spot. For example, you may have a spot in your flower bed that displays wonderful color in spring but that looks rather boring once the spring flowers fade. Eventually, you may be able to insert a new perennial here that will pick up the torch and furnish floral color in summer. But in the meantime, annual plants may be just the solution to cover up the gaping hole.