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annual vs perennial

Annual vs perennial plants

One of the most common gardening questions is the difference between annual vs perennial plants. In your own garden, you will most likely end up with a combination to take care of. Itโ€™s important to understand the key differences between them so you can care for them properly (and know what to expect to grow back every year!).

Annual plants live for less than one year, while perennial plants live for more than two years. Annual plants need to be replanted every year, but they tend to be less expensive at the garden center. Perennials tend to grow more slowly than annuals, and also have a yearly dormant rest period. Perennials are considered a long-term landscaping investment while annuals tend to be used to fill gaps of time or space, and to add color or quick curb appeal.

The fact that they are annuals vs perennials isnโ€™t the only determining factor in how you should care for them. Continue reading to learn about specific differences between perennials and annuals.

annual vs perennial plants

Annual vs perennial plants

Annual and perennial plants differ in many ways. While you canโ€™t usually tell just by looking at the plant, the differences become obvious after youโ€™re been gardening in the same spot for a few years.

The differences between annual plants and perennial plants include very different overall lifespan lengths, whether or not they experience a dormant rest period, whether they grow slowly or quickly, whether you need to buy them every year at the garden center (and how much they cost), and how they are used in garden and landscape design.

Lifespan

Annual plants have an expected lifespan of under 12 months. Perennials live for a minimum of three years.

Between these two common categories is an in-between group called โ€œbiennialโ€ plants, which have an expected life cycle length of two years. They grow their leaves during the first growing season, typically overwinter, and then flower and set seed in their second year before dying.

Not all perennials have a decades-long lifespan. Some are categorized as short-lived perennials while others are long-lived perennials. And then there are plants that are perennials in their native zone but are grown as annuals in cooler regions.

comparison list between annuals and perennials

Use in landscaping

Annual plants only live for one growing season, while perennial plants can live for many years. Annual plants are often used to fill in gaps in the garden or to add color and interest to a landscape. Perennial plants are often used as a long-term investment in a garden, as they can provide structure and interest for many years.

Up-front cost to purchase a single plant

Annual plants may be less expensive to purchase and plant than perennial plants, as they only need to be purchased and planted once per year. However, perennial plants may be a longer-term investment, as they can continue to grow and thrive for many years.

Dormancy

Perennial plants typically have a dormant period during the winter, during which they usually lose their leaves and become inactive. Annual plants do not have a dormant period. Most ornamental annuals are โ€œsummer annualsโ€ and die completely each fall (not just back to their roots).

Growth rate

Annual plants grow quickly and often produce a lot of foliage and flowers in a short amount of time. Perennial plants tend to grow more slowly and may not produce as many flowers in their first few years. That said, there are some pretty vigorous perennials out there (especially once theyโ€™ve been in the ground for a few years).

Annual replanting (versus coming back on their own)

Annual plants need to be replanted each year (unless they are โ€œself-sowingโ€ annuals). Perennial plants usually continue to grow in the same location for many years (as long as they are healthy). Some perennials do best if you split up the roots every few years, but the roots are generally long-lived overall.

Mexican marigold (Tagetes erecta)
Mexican marigold (Tagetes erecta) is a favorite annual flower to grow

Examples of annuals and perennial plants

Here are some examples of common annual and perennial plants that are grown in the garden. Most common food crops are annuals, while most ornamental grasses are perennials. Flowers are more of a mix, and there are some warm-climate perennials that are considered โ€œannualsโ€ in colder climates because they must be purchased from the garden center each year if you donโ€™t bring them indoors for winter.

Examples of annual plants

True annual plants complete their life cycle within a single growing season. Some examples of common annual plants include:

  • Zinnia (Zinnia elegans): Another popular garden flower, zinnias come in a range of sizes and colors including pink, red, white, and purple.
  • Sunflower (Helianthus annuus): These tall, bright flowers are a popular choice for gardens and make for great cut flowers.
  • Mexican marigold (Tagetes erecta): These brightly colored flowers are popular in gardens and are easy to grow. They come in a range of colors including yellow, orange, and red.
  • Cosmos (Cosmos): These annuals are known for their daisy-like flowers and come in a range of colors including pink, purple, white, and red.
  • Nasturtium (Tropaeolum): These annuals are known for their bright, colorful flowers and edible leaves and flowers. They come in a range of colors including red, orange, and yellow.
  • Petunia (Petunia): The plants are technically tender perennials, but are most commonly grown as if they were annual. They are popular for their large, showy flowers that come in a variety of colors including pink, purple, white, and red.
hostas with evergreens for a low-maintenance shade garden
These hostas combine with low-maintenance evergreen shrubs for a lower-light garden that wonโ€™t take too much work

Examples of perennial plants

Perennial plants are plants that live for more than two years and typically have a dormant period during the winter months. Some examples of common perennial plants include:

  • Peony (Paeonia): These flowering plants are known for their large, showy flowers that come in a range of colors including pink, red, and white.
  • Daylily (Hemerocallis): These plants are known for their brightly colored, trumpet-shaped flowers and are a popular choice for gardens.
  • Hosta (Hosta): These shade-loving plants are known for their large, attractive leaves and come in a range of colors and patterns.
  • Iris (Iris): These flowering plants are known for their tall, showy flowers that come in a range of colors, including purple, white, and even blue.
  • Lavender (Lavandula): These fragrant herbs are known for their purple flowers and are popular in gardens for their relaxing scent. These subshrubs usually grow as short-lived perennials.
  • Black-Eyed Susan (Rudbeckia): These flowering plants are known for their bright, yellow flowers and are a popular choice for gardens.
  • Aster (Aster, syn. Symphyotrichum novae-angliae): These flowering plants are known for their showy, daisy-like flowers that come in a range of colors including purple, pink, and white.

You can also consider flowering shrubs like roses or hydrangeas to be perennials, as they are expected to live for more than two years. Woody plants are sometimes separated out from herbaceous plants, but if youโ€™re just looking for a long-lived plant, also consider woody shrubs that flower.

Similarly, flowering bulbs are also perennials. They can be added to the garden between the plants we think of more commonly as ornamental perennials. This is especially true in cold climates where tulips bloom before some perennials even start to sprout up from their roots.

Zinnia (Zinnia elegans)
Annuals like zinnia (Zinnia elegans) need to grow quickly to produce mature seeds before frost!

Life cycle differences in annuals compared to perennials

An annual plant begins as a seed, germinates, blooms, produces its own seeds, and dies all in the same year. This usually takes the form of spring germination and vegetative growth followed by summer flowering and then setting seeds for early fall. The growing season isnโ€™t always from spring to fall however; some annuals are keener to cooler weather and live from fall to spring instead.

Perennial plants, on the other hand, are plants that repeat their growing process each growing season. They have hardy plant parts that keep them alive during the colder months. Their root systems (bulbs, tubers, rhizomes, etc) are what let them repeat their life cycle without a gardenerโ€™s assistance.

Mix of perennials and annuals in a border garden
You can mix up different types of plants for a really eye-catching garden

Blooming duration differences between the two

When comparing the blooming periods of these two types of flowering plants, you may note that perennials typically have a shorter blooming period than annuals. For this reason, many gardeners use a combination of both types of plants to ensure their garden is full of blooms for longer periods of time.

Annuals will usually bloom longer, especially if you โ€œdeadheadโ€ the plants. This is the process of removing any spent flowers from the plant. These include dried or dead flowers. Once these are removed from the plant, it is encouraged to produce more blooms because it is no longer using energy on dead blooms or flowers that are fading. Some annuals are โ€œself-cleaningโ€, meaning they donโ€™t need deadheading and will easily drop dead blooms.

fifty percent off perennials
Perennials tend to be expensive, so it makes sense to buy them in the fall when they are on sale!

A perennial plant tends to cost more than an annual

Since perennial flowers last longer, it makes sense that they would cost more upfront. They also donโ€™t do as well growing from seed to full plant, so they are sold as mature plants for your convenience. These potted plants, understandably, cost more than annuals do. Gardeners love perennials because they can plant them and forget about them without worrying they will die.

Planting annuals lets you change things up

Since annuals die each growing season, they make it easy for gardeners to determine whether they want to grow that same plant again the next year. If the plant didnโ€™t do well where it was placed, another one can be chosen the next year. Gardeners often enjoy switching up the plants and flowers in their garden, and annuals allow that luxury.

this one plant is now divided into three plants
Dividing a hosta plant up into three โ€œnewโ€ plants

Perennials can be divided out

Once perennials are mature and have reached their full height, it is important to maintain them. This often involves trimming or dividing out the plant to place elsewhere.

When you divide the plant, you create more space for it to grow, and it doesnโ€™t take over the space itโ€™s in. Divided regularly, the plant can be given to friends and family who may be looking for perennials in their garden. Share, sell, or plant the divided pieces in a new location!

hosta care guide
Hostas are a wildly-popular perennial, in large part because they donโ€™t take much work at all.

Perennials are usually lower maintenance (but not always)

When perennial plants are grown in their native region or a similar climate, they require very little maintenance. The elements will take care of the plant just fine. Plants added to a garden and climate they arenโ€™t adapted to will be fussy and will require more attention.

As a bonus, native plants will attract pollinators like bees and butterflies, providing habitats for small creatures. This promotes biodiversity in the garden and will help any local wildlife.

blue delphinium flowers at back of cottage border garden
Blue delphiniums are stunning perennials, but you have to tie the flower stalks to a stake every 6-12 inchesโ€ฆ

That said, there are low-maintenance annuals and high-maintenance perennials. They just arenโ€™t the norm (especially if youโ€™re growing plants that are well-suited to your individual growing location).

For instance, if you live in Zone 5 and are growing dahlias (which are only cold-hardy to Zone 8), you need to dig them up each fall and keep them above freezing until spring. Alternatively, if you live in Zone 9, while you can leave the dahlias in the ground, youโ€™ll have to dig up your tulips and store the bulbs in controlled conditions, as most tulips have a growing zone range of Zones 3-8 or so.

cosmos - annual

Incorporate both for a diverse garden

Adding both perennials and annuals to your garden will provide limitless shapes, textures, colors, and care options. The differences in the growing season will allow plants to fill in empty spaces throughout the year, and you can switch up the annuals as needed.

Choose complementary or contrasting colors for tons of fun. Add colorful annuals to perennial greens to transform the garden each season. The perennial plants regrow each year, and you can add annual flowers to mix things up. Perennials tend to take up more space, so add tender annuals that donโ€™t take up as much space around them.

Incorporate a variety of heights. Plant one plant that is tall and surrounded by a shorter annual plant, such as zinnias. These flowering plants will create showy blooms for taller perennials and plant types in early spring. Impatiens are perfect flowers to plant in the shade to add some color to any plant type in the garden. Keep in mind that it makes sense to plant perennials and annuals with similar water and light needs together to make your gardening experience easier.

Peony (Paeonia)

FAQs about annuals vs perennials

What is the main difference between annual and perennial plants?

The main difference between annual and perennial plants is their lifespan. Annual plants only live for one growing season, while perennial plants can live for many years.

Do annual and perennial plants have different growing habits?

Yes โ€“ usually. Annual plants tend to grow quickly and produce a lot of foliage and flowers in a short amount of time (since their time is limited!). Perennial plants tend to grow more slowly and may not produce as many flowers in their first few years.

How often do annual and perennial plants need to be planted?

Annual plants need to be replanted each year, while perennial plants can continue to grow in the same location for many years. The exception is self-sowing annuals, which readily re-seed themselves in the fall and then sprout anew each spring.

Do annual and perennial plants have different care requirements?

Annual and perennial plants may have different care requirements depending on the species and its preferences. Both types of plants typically need plenty of sunlight, water, and well-draining soil to thrive. Itโ€™s important to pay attention to the specific requirements of individual plants, as different types of annuals and perennials may have slightly different requirements.

References


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