Biennials - Plants which require two years to complete their life cycle.
Biennial plants have a life cycle of two years, so they germinate and grow one year, bloom and die the following. Everything which lasts longer than two years is perennial, which in practical terms usually means it grows and flowers for many years.
Biennial plants will overwinter and come back in the spring. During their 2nd year they will produce seeds and then die. Like annual plants, biennial plants are often part of nature's efforts to cover bare ground. Some common weeds such as mullein are biennials.
Read about plant classification here. Annual plants complete their life cycle in one growing season. Biennial plants are planted in one year, grow through the year, grow on and flower during the next year. Perennial plants grow strong year after year.
Examples of biennial plants are members of the onion family including leek, some members of the cabbage family, common mullein, parsley, fennel, Lunaria, silverbeet, black-eyed Susan, sweet William, colic weed, carrot, and some hollyhocks.
Most annuals and biennials are generally monocarpic.
Biennials - Plants which require two years to complete their life cycle. First season growth results in a small rosette of leaves near the soil surface. During the second season's growth stem elongation, flowering and seed formation occur followed by the entire plant's death.
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.
Roses are perennial flowers that can grow in zones 3-10. Plant your roses in late spring or early summer. There are many different types of roses, but they usually bloom on and off from spring to fall.
Actually, both! Most marigolds are annuals, but a few are perennials. Marigolds self-seed so they may appear to be a perennial when in reality, they are just coming back from seed.
One trait that most biennials share is that they are prolific self-seeders. This means that after they finish blooming they generate a lot of seed which often germinates in the summer or fall and starts the process all over again.
Many biennials are self-seeding, which means they release seeds, typically in the fall of their second year, to germinate and carry on their legacy come next spring. Avoid deadheading your biennials (snipping off dying flowers) in fall, and they'll give you a fresh garden the following year.
Alyssum. Alyssum is a warm zone perennial plant, which means it can bloom all year in climates like California. It has small, fragrant white, pink or purple flowers and grows best in full sun.
However, there are some advantages to growing biennials. Biennials tend to tolerate cold weather better than annuals. Although they don't come back year after year like perennials, they usually self-sow pretty easily, so there's no need to reseed every year.
The biennials that are grown for seeds, fruits and flowers are grown for two years, whereas those for edible roots and leaves are grown for one year only. Examples of biennials include: parsley, fennel, onion, cabbage, silverbeet and carrot.
Perennial plants regrow every spring, while annual plants live for only one growing season, then die off. Perennials generally have a shorter blooming period compared to annuals, so it's common for gardeners to use a combination of both plants in their yard. We're sharing a little bit about both types of plants below.
Yes, Hydrangeas are perennials: they go dormant in winter and come back in the spring on their own, assuming you've planted varieties suited for your Zone. Gardeners in northern Zones must take care to choose winter-hardy varieties.
Daylily (Hemerocallis)
Affectionally called the "perfect perennial," Daylilies survive through almost anything — fluctuating temperatures, irregular watering and so on. They come in a variety of colors and sizes, so you can find the right option to suit your garden or landscaping.
Be advised that Hibiscus is always one of the last perennials to emerge in spring. Be patient, even if you think it is dead, it most likely isn't. Its vigorous growth rate more than makes up for this late start, however. Japanese beetles find these plants especially delicious.
Lavender is a perennial herb in many areas - that is, perennial if it gets really good drainage. Growing in a pot is an ideal way to provide good drainage. However, if the potting mix is extremely fertile, the plant may grow leaves and stems rather than flowering.
If the plant is described as 'Hardy Perennial' it should stand up to average low winter temperatures and come up each year for several years. A 'Hardy Biennial' will build up a strong root and leaf system in its first year, survive the average winter and go on to flower, set seed and die off in its second year.
Perennials: Live for Three or More Years
An individual columbine plant, for example, may live for several years and then begin to die back. However, in that span it has produced plenty of seed. Peonies and daylilies, on the other hand, are long-lived, lasting for a decade or longer if given ideal growing conditions.
Biennials complete their life cycle in two growing seasons. In the first year they produce only roots, stems and leaves. In their second year they flower and form seeds, then die. (Annuals, meanwhile, germinate, grow, bloom, set seed and die within one year.)