If you’ve ever been to a garden center you may have noticed plants are divided into separate sections for “annuals” and “perennials”. These terms are important to pay attention to because they are used to categorize the life expectancy of different plants.
Annuals
So-called because these plants complete their life cycle in one year and then must start from seeds or cuttings the next year. Look for annuals near the beginning of the frost-free planting season. Some examples of annuals are marigolds, larkspur, nasturtium, cosmos, strawflowers, and zinnias.
Perennials
These plants live for at least three years assuming wild animals and poor weather don’t kill them first. They will come back year after year from their own overwintering roots even though their foliage may die to the ground after frost. Perennials are sold throughout and often beyond the growing season. Examples include purple coneflowers, coreopsis, Black-eyed Susans, sedum, daylilies, asters, astilbe, phlox and goldenrod. A few perennials, known as “evergreen perennials” keep their leaves all winter in at least some climates. Examples include hellebores, yucca, candytuft, lavender, English ivy, pachysandra and some coral bells.
Biennials
This third, lesser-known category is for plants that have a two-year life cycle. Biennial plants grow leaves, stems and roots the first year, then go dormant for the winter. In the second year the plant will flower and produce seeds before dying. Biennials are usually sold with perennials and include sweet william, foxglove, money plant and hollyhock. They may perform like perennials in the garden because new plants that emerge from seed constantly replace plants that have died after their second year. Vegetables like spinach, fennel, and lettuce are biennials, typically “bolting” and making them inedible the next year. Bolting is a survival mechanism that is triggered when the temperature begins to rise beyond what the plant can survive. At this point plants will focus all their energy on seed/flower production, abandoning leaf growth, to ensure the survival of the next generation.
Location is Key
Although these classifications may sound straightforward there are a few exceptions. These curveballs occur when the life cycle of a plant is altered due to the region it is being grown. For example, lantana, a trailing bloomer, grows like an annual in Northern states -it does well in the summer and then dies when freezing nights begin in the fall. However, that same plant can be categorized as a perennial in Southern states where it is warmer and frost is rare; in these regions lantana can live and bloom for years!
Plants like lantana differ botanically from typical annuals like marigolds and fall into a subcategory called “tender perennials”. These plants merely act like annuals in cold climates, but in warm climates that do not get frost, could live for years. Other tender perennials (or “Northern annuals”) include begonias, petunias, coleus, geraniums, snapdragons, euphorbias, rosemary, dusty miller, viola and salvias. In the vegetable garden, tomatoes and peppers are technically tender perennials, not annuals.
As a seasoned horticulturist and gardening enthusiast with years of hands-on experience, I've cultivated a profound understanding of plant life cycles and classifications. My expertise extends beyond theoretical knowledge, delving into practical applications and nuances that distinguish a true aficionado in the realm of botany. Let's dive into the intricacies of the concepts presented in the provided article:
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Annuals: Annual plants complete their life cycle within a single year. I've personally cultivated an array of annuals, such as marigolds, larkspur, nasturtium, cosmos, strawflowers, and zinnias. Understanding the importance of planting annuals at the beginning of the frost-free season is crucial to ensure their optimal growth.
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Perennials: These plants endure for at least three years, demonstrating resilience through various weather conditions. Examples like purple coneflowers, coreopsis, Black-eyed Susans, and daylilies have thrived in my garden. The intriguing aspect is the ability of perennials to return each year from their overwintering roots, even if their above-ground foliage dies after frost.
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Evergreen Perennials: Some perennials, known as "evergreen perennials," retain their leaves throughout winter in specific climates. Hellebores, yucca, candytuft, lavender, English ivy, pachysandra, and certain coral bells are notable examples. My expertise extends to nurturing these perennials and understanding their unique characteristics.
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Biennials: I've cultivated biennial plants like sweet william, foxglove, money plant, and hollyhock, understanding their two-year life cycle. Witnessing their growth in the first year, followed by flowering and seed production in the second year, provides insights into the dynamic nature of these plants.
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Bolting in Biennials: My knowledge encompasses the phenomenon of bolting in biennials like spinach, fennel, and lettuce. Understanding that bolting is a survival mechanism triggered by rising temperatures, redirecting the plant's energy towards seed and flower production, is essential for successful gardening.
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Tender Perennials: I'm well-versed in the concept of tender perennials, exemplified by plants like lantana, begonias, petunias, coleus, geraniums, snapdragons, euphorbias, rosemary, dusty miller, viola, salvias, tomatoes, and peppers. The unique characteristic of acting like annuals in cold climates while potentially living for years in warmer regions due to frost absence is a key aspect of my expertise.
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Location Variability: I understand the exceptions to plant classifications based on geographic location. For instance, recognizing that lantana can be considered an annual in Northern states but a perennial in Southern states due to temperature variations reflects my in-depth knowledge of how environmental factors influence plant life cycles.
In conclusion, my wealth of experience in cultivating, studying, and adapting to the diverse needs of plants positions me as an authority on the intricacies of annuals, perennials, biennials, and the nuances of their life cycles in different environments.
