Annuals Vs. Perennials: When To Use Them In The Garden

Ever wondered why some of your plants die after one season, while others come back year after year? If you've pondered that, you've likely noticed the difference between two categories of plants: annuals and perennials.

How do you know which type to use in the garden, and where? There are several reasons to plant both in your borders, beds, and containers. When planning the landscape, they can fill different needs, and using a mix gives you the best that both have to offer. Learn how annuals and perennials differ and how to use them in your landscape.

What Are Annual Flowers?

Annuals live for only one season. For example: You plant them; they bloom in spring, summer, fall, or winter; and then they die. At that point, they must be removed and replaced. Annuals require replanting season after season, year after year, though their blooming season tends to be longer than that of perennials. There are benefits to using annuals in the garden. Because they are temporary, they can fill gaps in the landscape and they’re a fun way to change last year’s look.

If growing from seed, they’re an economical choice too. If you like to create a different look, annuals make that possible in an established garden by adding new colors, heights, and styles. They grow quickly so they provide instant appeal to the yard. Annuals, or plants treated as annuals, include marigolds, zinnias, impatiens, begonias, coleus, and pentas.

What Are Perennial Flowers?

Unlike the one-and-done annuals, perennials come back year after year. They bloom one or more times a year and then go dormant until their blooming season arrives again. Unlike annuals, you purchase them once and then they spread, self-seed, or can be divided for more plants. Some, like butterfly bush and peonies, can live for a long time, saving money and work in the long run.

Native varieties support the environment by hosting pollinators and insects, and providing seeds for wildlife. Perennial determination can depend on where they are grown though. In colder areas, they may need to be overwintered or treated as an annual. Popular perennials include peonies, asters, roses, mums, coneflowers, hostas, and daylilies.

What Are Biennial Flowers?

Once you've learned all about annuals and perennials, turn your eye to a third category of plants: biennials. They combine the showy displays of annuals and the longer lifespan of perennials. These are plants that require two years of care to establish themselves before blooming. At two years, their life cycle is twice as long as that of other plants, but with correct care, they'll soon burst into bloom. Popular biennials include foxglove and sweet William.

Can Annuals Last Longer Than One Season?

It is possible to make your annual flowers perennials—in a way—with reseeding annuals. "After they finish flowering, their seeds drop to the ground, and then new plants magically appear the following year," the Grumpy Gardener says about self-seeding plants.

Some annuals can also be overwintered. The Grumpy Gardener explains, "There are two kinds of 'annuals.' The first are true annuals, like cosmos, larkspur, bachelor's-button, celosia, and common sunflower. After they flower, they set seed and die. The second are tender perennials we treat like annuals because of our cold winters. Remove the cold, give them winter sun, and they become perennials that you can enjoy for years."

How to Choose Between Annuals and Perennials

Undecided as to what to plant in your yard? Let us help you choose between annuals and perennials, or pair them to ensure there's always something green and blooming in your garden. "You don't need to plant a lot of flowers to make a big impression. Sometimes it takes several seasons to figure out what works in your garden.

This is why annuals can be a good choice," says Rebecca Reed, former associate garden editor at Southern Living. Annuals give us the flexibility to play with colors and shapes with a season of commitment, while perennials are a solid base we can rely on each year. "If you don't like the look, you can try something different next year. When you find a combo you do like, stick with it or plant perennials that will come back year after year," Reed says.

Planting Annuals And Perennials By Season

When planting annuals and perennials, consider which season the flowers will bloom when adding them to your Southern garden. Browse some of our favorite early-blooming perennials and annuals to start planning for spring. For sweltering Southern summers, choose heat- and drought-tolerant flowers.

In fall, introduce seasonal colors with annuals like violas and celosia and perennials like dahlias and dianthus while following this fall-planting guide. Winter is yet another opportunity for Southern gardens—either enjoy some color during the winter chill or plant seeds and bulbs for upcoming seasons.