6 Longest Blooming Annual Flowers You Need in Your Garden - Backyard Boss
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6 Longest Blooming Annual Flowers You Need in Your Garden

Annual flowers are a beautiful way to bring a burst of color to your garden. Though you do have to replant annuals each year, they are rewarding flowers to grow, and there are dozens of choices. Explore six of the longest-blooming annual flowers you need to plant in your garden this year!

1. Calibrachoa 

Calibrachoas close-up in purple and pink
Image credits: D Theodora via Pixabay

While technically an herbaceous perennial, calibrachoas are often treated as annuals. At first glance, these flowers look like miniature petunias. They come in assorted colors, including blue, purple, and yellow. Some hybrid types even come in striped varieties. 

They grow up to 10 inches tall and appreciate a mix of full sunshine and partial shade. They bloom in June, continuing through the summer until the first frost.  

2. Celosia

Yellow celosia close-up
Image credits: ignartonosbg via Pixabay

You can identify celosias by their bright flame-shaped flower heads that commonly attract bumblebees. These flowers come in many vivid colors, including burgundy, orange, and magenta. With the right conditions, including plenty of sunshine, they can grow up to 3 feet tall, so give them lots of growing space. Celosias bloom from summer (June) until the first frost. 

Pro Tip: Celosia leaves, stems, and young flowers are edible. When the plant matures, its leaves taste similar to spinach. However, once the plant is fully developed, the leaves turn bitter.

3. Carolina Geranium

Geranium carolinianum
Image credits: sonnia hill via Openverse

If you’re looking to build a more low-maintenance garden, Carolina geraniums are the annual flower for you. They are very resilient flowers that can survive heat and dry spells. They grow pretty low to the ground and don’t mind extra sun as they bloom.

Their five-petaled flower heads grow in white or pink clusters. Carolina geraniums have a blooming period that starts as early as March and lasts through the end of July, making them one of the earliest annuals to bloom in the new year.

4. Garden Cosmos

Garden cosmos pink variety
Image credits: Manfred Richter via Pixabay

Garden cosmos grow in bright pink and white clusters and bloom all summer until fall. These annuals can grow up to 6 feet tall. Their height and large petals make them vibrant statement flowers to include in your garden.

Pro Tip: It can take up to seven weeks for these flowers to bloom if you grow them from seeds. Keep this in mind when scheduling your planting. Start early or even sow your seeds indoors for a spring gardening head-start!

5. Sweet Pea

Sweet pea in pink close-up
Image credits: Alicja via Pixabay

Annual sweet peas are best known for their refreshing and sweet scent. These types of sweet peas can grow up to 10 feet tall, with thick petals and vine-like stems. For this reason, it’s a good idea to grow them alongside a garden lattice or gate; They’ll be able to climb along it for extra support.

These flowers appreciate bright sun and develop pink, purple, and white petals. In colder climates (zones 8 to 10), sweet peas have a very long blooming period that starts in March and continues through the summer until August. If you live in a milder climate it’s possible to enjoy their blooms year-round.

6. Snapdragon

Snapdragon with bee flying
Image credits: Ralph via Pixabay

Snapdragons are fun-looking flowers that grow petals in the shape of a mouth. They also bloom in almost every color of the rainbow, including red, orange, pink, and violet. They love the sun and can grow anywhere between 6 inches to 3 feet tall. 

Snapdragons also have a strong floral fragrance that attracts bumblebees. Their blooming period starts in the early summer and continues through the fall.

Fun Fact: These flowers grow as perennials in the wild. 

Why Plant Annual Flowers?

Bee on flower pollinating
Image credits: Nottmpictures via Pixabay

Now that you’ve learned about which longest-blooming annual flowers to add to your garden, it’s also valuable to know what makes annuals so remarkable.

They Attract Pollinators

By choosing annual flowers, you can support local biodiversity by attracting pollinators! Birds, bees, and butterflies will appreciate the abundance of pollen (protein and fat) and nectar (sugar) for energy from your plants. 

They Offer More Bloom for Your Buck

At first thought, perennial flowers allow you to get the most out of your money because of their yearly return. However, it takes quite a few weeks for them to emerge from their winter hibernation, and they won’t stick around for long after. Planting annuals intermittently around your perennials allows you to fill your garden space with a continuous pop of color while waiting for your perennials to bloom. 

They Allow for Garden Design Flexibility

Because annual flowers only stick around for the season, you’ll have lots of freedom when planning your garden design from year to year. You can easily remove their roots from your garden bed at the end of the season. You won’t be tied down if you want to try something different with your garden layout or location next year. Better yet, there are even annuals that bloom in winter and spring! This is because cooler evenings and seasonal temperature drops can promote flowering.

Enjoy the Colorful Seasons Ahead

These six annual flowers are some of the longest-blooming plants to add to your garden space this year. You can plant them in your garden bed, containers, windowsill boxes, or decorative pots. No matter which annual flowers you choose, their bright petals will paint more color into your garden.

Which annual flowers will you be planting in your garden this year? Help inspire others by sharing your gardening ideas below!