Simply Put: Annuals
In the horticultural world, there are three major groupings of plants intended for planting outdoors: annuals, perennials and woody plants. The differences blur a little bit because horticulturists are a more relaxed group of people than botanists, who tend to be very serious about this sort of thing. And the garden center strain of horticulturist tends to be so relaxed that we slump.
Just for the record, botanists are the basic science folks. They worry about things like what plants grow on some ledge in Patagonia and who first named them in 1712. Agronomists are applied science folks that work with field crops (wheat, corn, alfalfa) and horticulturists are also applied science folks that work with the small scale stuff—vegetables, fruits, and ornamental (decorative) plants. We’re the frosting on the cake.
So: first. Annuals.
Annuals are plants that are programmed (Mother Nature 3.0) to live their entire lives in one year (an annual life cycle). That is, they start out as a seed, grow, flower, make more seeds to start the next generation and die, all within one year or less. In the garden center, some plants that would live for more than a year in a warmer climate are sold as annuals because they croak when it gets cold (begonias, for example) or hot (pansies). So, for your purposes as a garden center shopper, you get one growing season out of an annual, and if you want to use it again next year, you have to replant.
The primary advantage to annuals is a long blooming season. A petunia planted in May should still be blooming in September. You want to plant something in a shady spot and have flowers all summer? You must plant an annual. When shopping, you will find annuals that flower well in cool weather—they may tolerate some frost–or hot weather, but not both.
When we in the garden center biz are talking about annuals we are talking about Flowers. Although vegetable plants are often annual in behavior, we just call them “vegetables.” Herbs may be annual (basil) or perennial (thyme), but we sell them by use, which is “herbs.” A bonus to you as a customer: people selling annuals (and vegetables) don’t get real hung up on Latin names. So, you can safely walk up to someone and ask for a marigold and not have anyone get snooty about it.
Because they are so colorful and relatively inexpensive to boot, garden centers sell more annuals than anything else–usually as started plants–although many annuals can be started as seed sown directly into the garden. (Some of the newer annuals such as Wave Petunias or Supertunias are grown by specialist growers from cuttings instead of seed.)
Annuals look best when planted in groups for big blocks of color, mixed or as a single variety. Gardening with annuals became popular in the late 1800’s. The practice of planting annuals in flower beds was called “bedding out,” and gave rise to the term “bedding plants” which is still used as a synonym for annuals.
Next time: perennials, woody plants, and biennials.