By: Mary Ellen Ellis
Annual, perennial, biennial differences in plants are important to understand for gardeners. The differences between these plants determine when and how they grow and how to use them in the garden.
The annual, biennial, perennial meanings are related to the life cycle of plants. Once you know what they mean, these terms are easy to understand:
It’s important to understand the life cycle of plants before you put them in your garden. Annuals are great for containers and edges, but you must understand you’ll only have them that one year. Perennials are the staples of your beds against which you can grow annuals and biennials. Here are some examples of each:
Some plants are perennials or annuals depending on the environment. Many tropical flowers grow as annuals in colder climates but are perennials in their native range.
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If you are a novice gardener, one of the basics to learn is the difference between annual and perennial plants. The simplest way to differentiate between the two is to understand that annuals are plants that have a one-year life cycle. They grow from seed, bloom, set seed again and then die. Sometimes, if left to set seed, the seeds will germinate the following year. An annual's blooming season lasts from spring to frost. Impatiens, marigolds, zinnias and petunias are common examples of annuals.
Unlike annuals, perennials are flowers that live for three or more years. Their bloom time is generally within a short two- to three-week span, although this can also be extended by regular deadheading (removing spent blooms). Each year the top portion of the plant dies back but the next spring it regrows from the same root system. Once established, perennial plants can be divided in spring or fall to produce new plants. They can also be propagated from seeds or cuttings. Common varieties of perennials include coneflowers, tickseed and coral bells.
When selecting perennials, make sure the particular plant is hardy to your gardening zone. You can find out your zone on The National Gardening Association's website (see Resources). Select plants with light, soil and water requirements that match the location where they will reside.
The short answer is that annuals don't come back, but perennials do. Plants that flower and die in one season are annuals—although many will drop seeds that you can collect (or leave) to grow new plants in the spring. Annuals will also typically bloom all season until frost, so you get consistent color and showy blooms. Another advantage is that these plants can typically go in the ground any time, even in midsummer, to refresh your beds.
Perennials, on the other hand, come back for many seasons. While the top portion of a perennial dies back in winter, new growth appears the following spring from the same root system. While this makes planting easier, there are some drawbacks. Perennials tend to have less flashy flowers and bloom for a shorter period of time, usually just two to six weeks. Perennials also tend to do best when planted in the fall or spring, no later than six weeks before the ground freezes (about mid-November for most of the country).
To further complicate things, some annuals become perennials in warmer climates, when the lack of a hard frost allows them to keep growing. And just to make life interesting, some plants take two seasons to flower they’re called biennials.
Lettuce is an example of an annual plant
Annual plants are plants that die every year. Their whole life span (from germination of the mother seed to production of the next generation seeds) occurs within the same growing season. They need to be replanted once the plant dies.
Depending on the species of the plant, one seed-to-seed life cycle for annual plants may be completed in a single month or up to several months. Once a plant produces mature seeds, it dies but may leave a number of seeds. These seeds will remain dormant until the right season comes. When it is time for them to grow and the conditions are right, the seeds germinate and then go through the same cycle. Typically, annual plants grow one generation every year.
Most annual flowering plants bloom for a long period of time. In the countries that experience winter, annual flowering plants, like petunias and zinnias, add beauty and color to the garden from spring until autumn.
Common examples of annual plants are corn, wheat, rice, lettuce, beans, peas, zinnias, and marigolds.
Black-eyed Susan is an example of a biennial plant
Biennial plants are plants that end their life cycle after two years. During the start of the cycle, the plant grows its vegetative structure (i.e. leaves and stems). The tiny leaves and short stems do not grow far from the soil. After this stage, the plant stems grows rapidly. The plant also begins to produce flowers and seeds. At the final stage – after two years – the whole plant dies.
Biennial flowering plants bloom very well. Examples of biennial plants include Black-eyed Susans, parsley, carrots, and leeks.
Artichokes are examples of perennial plants
Perennial plants, on the other hand, are plants that continue to grow for several years. There are two kinds of perennial plants: deciduous perennials and evergreen perennials. When the weather gets too cold, the top part of a deciduous perennial plant normally dies but its roots underground survive. Once the weather gets warmer, the top part grows back and gets its energy from the surviving roots. Evergreen perennial plants, like pine trees, survive the winter and they are commonly used as landscape plants in areas that experience intense cold weather.
Perennial flowering plants, like tulips and lilies, bloom for a short period of time, usually for only a week or two every year. Because perennial plants are long lasting, gardeners do not normally replant them unless the plant itself needs to be replaced because of plant problems.
Perennial plants do not stop growing and producing flowers and seeds even after a couple of years. In fact, many perennial plants can live for several decades. Examples of perennial plants include artichokes, rhubarb, eggplants, most fruit trees, and most herbal plants.
It is important to note that some annual plants may become perennial plants when they are planted in their native climates.
Sweet William is one of those classic cottage flowers that you often see when walking through the various rural parts of the countryside. It is inherently old fashioned looking, with large bushes of circular red, pink, and white flowers. It isn’t exactly retro so much as it is old school, so make sure that it suits the style of your garden if you decide to use it.
It is great at attracting bees and other pollinators, so again it can make for a good companion plant. It can reseed, though, so be careful not to let it overrun your garden.
Sweet William is a bit pickier than its biennial counterparts. It likes the full sun, although it can tolerate some shade, and prefers its soil loose, well-drained, rich with nutrients, and slightly on the alkaline side. It is also a fan of fertilizers.
On the other side of the old-fashioned scale, hollyhock is indeed more retro than old looking. It has a gorgeous vertical-style stem and flower pattern, and the petal arrangement just reminds you of the good old days.
It can come in a variety of colors, but to best make use of its distinct appearance, you should be planting these in pink.
This level of beauty doesn’t come easy, though. Hollyhock is fussy, and it needs full sun and a rich soil that is moist and well-drained.
Hollyhock can, in fact, live longer than the two years of a biennial with a bit of care and patience, although generally speaking, if you don’t allow it to seed, it shouldn’t.
Also known as the money plant, the jade plant is a great example of an indoors biennial. It is a fairly old school plant that has traditionally been given as wedding gifts. The name of money plant is derived from its roots in feng shui from China.
The plant likes a fair bit of natural light and likes to be watered moderately. Don’t overdo it, but don’t let the plant suffer from drought either.
Aside from that, these plants are fairly easy to grow. Feed them every three or so months, and you should have a houseplant that lasts you as long as you want it to.
Really useful and easy to understand advice foe a complete beginner. Thank you., will.use all the time
This has been the best firm of information I have found. I am a beginner in terms of gardening and everywhere else I have looked for info has been confusing and lots of lingo talk.
Definitely be using this website again.
Fantastic – simple and easy explanation to someone learning everyday.
What does a hardy perenial do does it come up every year
Thanks for your comment. Yes, perennials should flower every year. Hardy plants can resist adverse growing conditions, such as frost, cold winds or drought, meaning they should survive (depending on the plant) year after year.
I hope this helps!
Hi I have two very healthy holly bushes one female one male I have not had any berries as yet I have had these bushes about 3 years do I just have to be patient?
Thank you for your comment. There are a number of reasons why a holly bush may not be giving out berries. Firstly, make sure they are definitely male and female and not male and male or female and female. Secondly, if they are the correct sexes, they need to be planted within 200 yards of each other. Some varieties of holly do not produce berries at all so check that they are definitely berry producing trees. It can also take from 3 to 5 years for a holly to start producing berries, so unfortunately you might have to wait for another two years, but fingers crossed and hopefully they will come sooner, rather than later. Remember not to over-prune and make sure they are getting the right amount of water and sunlight. I hope this helps!
I replacemy plants in the spring and fall. Which are best for fall?