15 Annual Flowers That Bloom All Summer Long

Colorful zinnias in the garden. — glennimage / Getty Images. Credit:
glennimage / Getty Images

Annual flowers are beloved for their showy, colorful blooms that bring seasonal interest to the garden. One downside? They only have one growing season, unlike perennials. But don't let that deter you from planting them. Even though you need to re-plant annuals every year, these plants are extremely versatile and enjoyed by beginner and experienced gardeners alike. They're great for filling in blank spots in border gardens, look lovely in cutting gardens, and grow well as container plants. To get the most out of your annuals, we asked gardening experts to share varieties that bloom all summer long.

PeggyAnne Montgomery, horticulturist and bulb expert for Flowerbulbs.com, a website dedicated to providing information about flower bulbs
Brian Phiel, associate director of outdoor gardens at Longwood Gardens, a botanical garden in Kennett Square, Pennsylvania

01 of 15

Lantana

Perfect for beginner gardeners or those battling tough growing conditions, annual lantana (Lantana camara) is virtually indestructible. "Lantana thrives in hot, dry sun, won't be eaten by rabbits or deer, invites hummingbirds and pollinators, doesn't need deadheading, and actually blooms all summer," says PeggyAnne Montgomery, horticulturist and bulb expert for Flowerbulbs.com. "In mid-summer or so, cut them back by a third to a half to promote compact growth and a fresh round of blooms."

Zones: 9 to 11
Size: 6 to 12 inches tall x 6 to 30 inches wide
Care requirements: Full sun; average, well-drained soil

02 of 15

Border Dahlia

Depending on where you live, dahlias (Dahlia spp.) are either perennial or annual; typically, gardeners in zones 7 and below grow them as annuals. "Dahlias are grown from tubers, but smaller varieties are often sold already in bloom as annuals—they are often called border dahlias," says Montgomery. "They will bloom all summer and into fall." Since they're typically purchased after they've flowered, you can expect a much longer bloom time from border dahlias. Deadhead spent flower heads to encourage more growth.

Zones: 8 to 11
Size: 12 to 18 inches tall x 24 inches wide
Care requirements: Full sun; evenly moist, well-drained soil

03 of 15

Narrowleaf Angelon

angelonia flower — kuenlin / GETTY IMAGES

Narrowleaf angelon (Angelonia angustifolia) is an upright annual that loves the heat of summer and will put on a beautiful show all season long. "Floral spikes filled with snapdragon-like flowers bloom in shades of white, pink, or purple on stems with narrow green leaves," says Brian Phiel, associate director of outdoor gardens at Longwood Gardens. You should plant this fragrant bloomer in spring after the threat of frost has passed.

Zones: 9 to 11
Size: 18 inches tall x 12 inches wide
Care requirements: Full sun; moist, fertile, well-drained soil

To keep annuals blooming all summer long, regularly remove spent flowers (a process called deadheading). This encourages plants to produce new blooms instead of putting energy into seed production.

04 of 15

Tuberous Begonias

Grown as annuals in most of the country, tuberous begonias (Begonia × tuberhybrida) bloom all summer. "They have attractive, waxy foliage and bloom in bright, saturated colors," says Montgomery. "They do not like scorching sun—give them a location with plenty of morning light and filtered light in the afternoon." Remove spent flowers and wilted leaves to keep the plants healthy and to encourage continuous blooms.

Zones: 9 to 11
Size: 12 to 18 inches tall x 16 to 18 inches wide
Care requirements: Filtered sun; humus-rich, well-drained soil

Garden Cosmos

Annuals are known for having showy, bright blooms, and cosmos (Cosmos bipinnatus) are no exception. "An airy, fine-textured annual with large daisy-like flowers, cosmos make great additions to cut bouquets," says Phiel. "Available in colors ranging from magenta to white, yellow, and orange, these flowers are also known for attracting bees and butterflies." They're easy to grow from seed and should be sown just before your area's last frost date.

Zones: 10 to 11
Size: Up to 4 feet tall x 2.5 feet wide
Care requirements: Full sun; average, well-drained soil

06 of 15

Firecracker Plant

Firecracker plant (Cuphea ignea), loves heat and sun, so it's a great summer annual variety. "The bright orange flowers are small but produced in abundance and truly flower all summer," says Montgomery. "In frost-free climates you can grow it as an evergreen perennial, but it's generally grown as an annual in most of the country." The pollinator-friendly plant will welcome hummingbirds, butterflies, and bees to your yard.

Zones: 9 to 11
Size: 18 to 28 inches tall x 12 to 24 inches wide
Care requirements: Full sun; well-drained soil

07 of 15

Zinnia

A popular flower for gardeners, zinnias (Zinnias spp.) are heralded for being a tough, easy-to-grow annual that blooms non-stop all summer. "They make outstanding cut flowers and are loved by butterflies," says Montgomery. "They come in a wide variety of colors in single, semi-double, and double forms." Note that zinnias are susceptible to powdery mildew in the fall, but good air circulation can help with this.

Zones: 2 to 11
Size: Depends on the variety
Care requirements: Full sun; well-drained soil

08 of 15

Hibiscus

Hibiscus (Hibiscus spp.) has exotic blooms that open wide in shades of red, orange, yellow, and pink and often have a contrasting eye color. "It can be grown in large containers or in the ground," says Montgomery. "Prune away dead leaves and spent flowers. An organic fertilizer is appreciated." You can plant the tropical flower once nighttime temperatures are above 50 degrees Fahrenheit.

Zones: 5 to 11
Size: Depends on the variety
Care requirements: Full sun; well-drained soil

09 of 15

Globe Amaranth

A compact annual that makes an excellent dried flower, globe amaranth (Gomphrena globosa) will put on a show all summer. After its growing season, you can dry this flower and use it as décor in your home thanks to its bright bracts, which retain their color. "Cultivars have expanded the range of available colors to include red, pink, purple, lilac, violet, and white," says Phiel.

Zones: 10 to 11
Size: 18 inches tall x 12 inches wide
Care requirements: Full sun; average, well-drained soil

10 of 15

Celosia

A versatile annual, celosia can be planted in flower beds, border gardens, and containers. "This long-blooming annual has showy feather-like flowers on erect stems," says Phiel. "Flowers bloom throughout summer and into fall and are stunning in arrangements or when dried." The plant thrives in hot, humid weather, making it ideal as a summer annual flower.

Zones: 10 to 11
Size: 18 inches tall x 12 inches wide
Care requirements: Full sun; average, moderately fertile, well-drained soil

11 of 15

Paris Daisy

A cheery way to fill in blank spaces in a perennial garden, Paris daisy (Argyranthemum frutescens) has flowers in pink, yellow, or white, which surround yellow centers. "It blooms throughout the summer, but slows down in the heat," says Phiel. "Some cultivars have features such as double flowers or blue-green foliage. Newer cultivars do not need deadheading."

Zones: 10 to 11
Size: 2.5 feet tall x 2.5 feet wide
Care requirements: Full sun; average, well-drained soil

12 of 15

Mandevilla

This tropical flower will make you feel like you're on vacation when standing in your own backyard. It's a fast grower and has large, fragrant flowers that bloom in shades of pink, red, white, or yellow. "Give this a special place in the garden where you'll be able to enjoy it every day," says Montgomery. Mandevilla (Mandevilla spp.) flowers are self-cleaning, so they don’t need deadheading, but they will require vertical support. "Its waxy, deep green foliage is highly pest and disease-resistant," she says.

Zones: 10 to 11
Size: Depends on the variety
Growing conditions: Full sun; average, moist, well-drained soil with some organic matter

13 of 15

Marigold

Marigolds (Calendula officinalis) are a wonderful companion plant that keep harmful bugs like aphids away from your garden. These pollinator-friendly plants produce bright, showy blooms that show off from early summer throughout fall.

Zones: 2 to 11
Size: 1 to 2 feet tall x 1 to 2 feet wide
Care requirements: Full sun; moist, well-drained soil

14 of 15

Petunia

Petunias (Petunia spp.) are one of the most popular flowering annuals thanks to their bright, cheerful blooms that fill gardens with color from spring until the first frost. There are multiple varieties of petunias, from grandiflora (which have the largest blooms) to milliflora (which have the smallest blooms). Make sure you plant this beloved bloomer in an area with a lot of sunlight.

Zones: 10 to 11
Size: 6 inches to 18 inches tall x 12 to 36 inches wide
Care requirements: Full sun; moist, well-drained soil

15 of 15

Cornflower

Cornflower (Centaurea cyanus) is a hardy, low-maintenance annual that blooms from June to September, putting on a show in the garden with its blueish-purple blooms. It's tolerant of poor soils and can withstand periods of drought, making it a great option for the hands-off gardener.

Zones: 2 to 11
Size: 1 to 3 feet tall x 1 to 2 feet wide
Care requirements: Full sun to partial shade; well-drained soil