What is the difference between annual flowers and perennial flowers?
Annual plants complete their lifecycle in one growing season. Familiar annuals include Petunias, Marigolds, Impatiens, Million Bells, and most of the showy, long blooming plants that we use in our hanging baskets and patio containers. Because they live for only one season, annuals put all of their energy into producing abundant flowers from spring through fall. Annual plants must be planted each spring (“annually”). Just to confuse the issue, many plants treated as annuals in Wisconsin are actually perennials which are not cold hardy enough to survive winter here. Examples include Guara, Mandevilla, and Rosemary.
Biennials are plants that complete their life cycle in two years. The first year they produce only foliage, usually low to the ground. In their second year of life they grow to their full height, bloom and produce seeds. If allowed to self-sow these plants will produce seedlings and persist in your garden from year to year. Since seedlings will decide for themselves where to grow and might not come up exactly where the gardener desires, biennials are best suited to a cottage garden or informal flower bed. Familiar biennials include Hollyhocks and Foxglove.
Perennials are plants that survive in the garden for multiple years. Some live for decades while others may live only 3-5 years. Because perennials need to devote energy to root development, they cannot use all of their energy on flowers and therefore bloom for a shorter time than annuals. Most perennial bloom for 3-4 weeks but some particularly long blooming ones may provide as much as 8-10 weeks of flower color. Familiar perennials include Peonies, Daylilies, Hosta Iris, and Coneflowers.
The cold hard truth about annuals. Are they all the same?
Annual plants can be viewed a few ways: true annuals, winter annuals, and half hardy annuals. True annuals, like African Marigolds which can bloom all growing season if deadheaded, stick around the garden all year before they die. For winter annual gardening, choosing the right annuals and the correct varieties is key to creating a colorful planter, window box, or garden bed at your home. Growing them requires taking into account low light levels, cooler soil temperatures, and the occasional extreme weather of systems of Wisconsin’s polar vortices. Half hardy annuals describe plants that will tolerate some frost, but not a long freeze, such as China asters or zinnias.
Why grow annuals instead of, say, perennial coneflowers, hostas, salvia, or compass plant?
If you have planted lots of perennial flowers, you are familiar with their longevity. You purchase flower seedlings (or start your own), and plant them in a location best fitted to their needs. You’re able to nurture them year after year, fertilize and water them.
Annual plants afford you the seasonal customization of your beds, pots and hanging baskets; They are floriferous, so they will brighten up mixed borders with non-stop color. Another important aspect about annuals is they often germinate quickly and easily, and they set a lot of seed. Once established, many annuals need minimal upkeep in the form of watering and fertilizing; they are very simple to grow. Annual plants allow you to change your mind next season! Perhaps next year you may try a different color scheme.