17 Stunning Annual Flowers with True Blue Blooms
Discover garden gems that deliver rare azure blooms and effortless seasonal color.
17 Annual Flowers with Beautiful Blue Blooms
When spring makes its arrival, local garden centers come alive with annuals in a dazzling array of colors. For those looking to make a bold and elegant statement, few choices are as eye-catching as true blue-flowering annuals. Despite being rare in the plant world, these blue blooms capture serenity and a splash of cool color unlike any other. In this guide, you’ll discover 17 annual flowers that boast authentic blue colors along with their growing requirements, standout features, and care tips. Whether you’re refreshing your garden beds or perking up patio pots, these blue treasures will not disappoint.
Why Choose Blue Annual Flowers?
Blue is often considered a rare and sought-after color in the flower world. Many so-called “blue” flowers often skew to violet or purple, but the selections below are prized for their genuine blue tones. These annuals let you:
- Add uniqueness to your garden palette.
- Attract pollinators, such as bees and butterflies, who are drawn to blue and purple tins.
- Pair well with a wide range of other bloom colors, enhancing garden harmony and contrast.
- Experiment each season thanks to their annual growth habit â you can reinvent your garden every year!
17 Gorgeous Blue-Blooming Annuals
Below you’ll find the top annual picks for truly blue blossoms, including their botanical names, preferred sun conditions, height, and hardiness zones.
| Common Name | Botanical Name | Sun | Height | Zones | Blue Hue |
|---|---|---|---|---|---|
| Bachelor’s Button | Centaurea cyanus | Full sun | 24â36″ | 2â11 | Sky blue |
| Morning Glory | Ipomoea tricolor | Full sun | 15′ vine | 3â10 | Light to sky blue with white throat |
| Floss Flower | Ageratum houstonianum | Fullâpart sun | 6â36″ | 2â11 | Pale to vivid blue |
| Blue Daze | Evolvulus glomeratus | Full sun | 10â24″ | 8â11 | Faded blue |
| Fanflower | Scaevola aemula | Fullâpart sun | 8â14″ | 10â11 | Soft blue |
Below is a closer look at each flower, their appearance and notable varieties, plus planting & care tips for garden success.
1. Bachelor’s Button (Cornflower)
Bachelor’s Button (Centaurea cyanus) is a garden classic, valued for its bright sky-blue flowers that stand 24â36 inches tall. Not only do they add cool tones to flowerbeds, but theyâre also edible, drought-tolerant, and attract pollinators. Sow directly into the ground in early spring or late summer and thin seedlings for best effect. They perform best in full sun and bloom from early summer into fall. ‘Blue Boy’ is an especially popular cultivar thanks to its intense blue color, making it a superb choice for cutting gardens and fresh bouquets.
2. Morning Glory
Morning Glory (Ipomoea tricolor) produces magnificent vines with large blue trumpet-shaped flowers and white throats. The beloved ‘Heavenly Blue’ cultivar is the gold standard for true sky-blue blooms. Perfect for trellises, pergolas, and fences, the vines can quickly reach up to 15 feet. Plant in full sun and ensure supports for climbing. Note: Some parts may be toxic if ingested, so site with care if children or pets are present.
3. Floss Flower
Floss Flower (Ageratum houstonianum) features clusters of fluffy, soft blue to lavender flowers resembling pincushions atop lush green foliage. Plants range in height from 6 to 36 inches and produce dense summer blooms ideal for borders or containers. Cultivars like ‘Leilani Blue’ or ‘Blue Horizon’ are especially admired for their bright blue hues and are excellent as cut flowers. Easy-going in the garden, they’re tolerant of various soils and attract butterflies.
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4. Blue Daze (Evolvulus)
Blue Daze (Evolvulus glomeratus) stands out with its soft, faded blue flowers featuring fuzzy white centers. Plants form a tidy, low mound, making them ideal for the front of borders, containers, or as a lush groundcover. They bloom profusely from spring through the first frost, appreciate full sun, and are reliably deer resistant. Consider cultivars like ‘Blue Daze’ and ‘Blue My Mind’ for the truest blue color.
5. Fanflower
The Fanflower (Scaevola aemula) produces unique fan-shaped blue blossoms that create a cheerful, continual display throughout the season. Well-suited for hanging baskets, window boxes, or cascading over walls, these plants appreciate full to part sun and are a favorite of pollinators. Fanflowers are heat and drought tolerant, thriving in summerâs hottest stretches.
6. Lobelia
Lobelia erinus is known for its delicate, intense blue flowers that smother compact mounds or spill beautifully from containers. Often used for borders and baskets, Lobeliaâs blue is rich and clean, with varieties like ‘Crystal Palace’ prized for their clear, saturated tones. Full to partial sun and moist soil help maintain healthy plants and abundant blooms.
7. Petunia
Modern petunia hybrids offer a range of blue shades from icy powder to deep indigo. Varieties like ‘Sky Blue’ and ‘Ultra Blue’ fill baskets, beds, and window boxes with vibrant displays throughout summer. Versatile and easy to grow, petunias benefit from fertile, well-drained soil and regular deadheading to keep flowering vigorously.
8. Love-in-a-Mist (Nigella)
Nigella damascena, often called Love-in-a-Mist, features intricate, star-shaped blue flowers surrounded by fine, feathery foliage. The unique seedpods add continued garden interest into fall and can be dried for crafts. Sow directly where you want them to grow, and enjoy prolific blooms with minimal fuss.
9. Delphinium
Annual varieties of Delphinium evoke elegance with upright spires of bright blue blooms. Though many delphiniums are perennials, gardeners can start annual forms from seed for summer displays. Provide rich soil, ample sunlight, and staking if needed to support tall flower spikes.
10. Baby Blue Eyes (Nemophila)
Nemophila menziesii (Baby Blue Eyes) carpets shady beds or containers with low, spreading plants covered in small, sky-blue flowers. Ideal for creating a “meadow” feel or cooling effect under trees, these beauties grow well in partial shade and moist, loose soil.
11. Ageratum
Ageratum (again highlighted for its blue forms, especially in bedding annuals) repeats its importance, with cultivars offering a palette from soft to vivid blue. It’s a maintenance-friendly choice, continuing to flower until hard frost and thriving in mass plantings for color impact.
12. Phlox
Annual phlox (Phlox drummondii) displays clusters of small blue blossoms held above lush green growth. Perfect for sunny beds or containers, they bloom profusely with little attention, adding steady color to borders and garden edges.
13. Salvia
Salvia farinacea cultivars, like ‘Victoria Blue’, send up spikes of rich blue flowers that attract bees, butterflies, and hummingbirds. These upright, sun-loving plants provide long-lasting color in both landscape and cut flower arrangements.
14. Pansy
Pansies (Viola x wittrockiana) offer cheerful faces in a variety of blue shades, from soft powder to vibrant cobalt. Ideal for early spring or fall color, they tolerate cool temperatures and bring charm to beds and containers.
15. Torenia
Torenia fournieri is the “Wishbone Flower,” featuring blue tubular blooms with yellow and white markings. These shade-loving annuals brighten corners where sun-lovers may not thrive and flower non-stop through the warm season.
16. Larkspur
Annual Larkspur (Consolida ajacis) brings tall spires of soft blue flowers to spring gardens. Hardy and easy to start from seed, these add drama to the back of beds or as cut stems for vases.
17. Browallia
Browallia spp., known as bush violet, is a lesser-known annual gem featuring blue to violet-blue star-shaped flowers on compact plants. Browallia loves dappled shade, making it a fine companion in spots difficult for other annuals.
Tips for Growing Blue Annual Flowers
- Sun Exposure: Most blue-flowering annuals prefer full sun, but some (like Nemophila and Torenia) tolerate partial shade.
- Spacing: Pay attention to variety height and spread; group blue annuals together or pair with yellows, whites, and oranges for striking contrast.
- Watering: Water consistently, especially when establishing new annuals, but avoid waterlogged soil unless specified.
- Feeding: Apply an all-purpose fertilizer at planting and again midseason for lushest blooms.
- Deadheading: Remove spent blossoms to encourage continued flowering throughout the season.
Designing with Blue Annuals
For dramatic effect, plant blue-flowering annuals in mass or drifts for a soothing wave of color. Use them to:
- Soften border edges with trailing types like Lobelia or Blue Daze.
- Create a focal point with tall, spiky forms such as Delphinium, Salvia, or Larkspur.
- Add interest to shade spots using Torenia, Browallia, or Nemophila.
- Enhance container arrangements with compact blue-flowering varieties and overflowing forms.
Best Blue Cultivars Worth Trying
- ‘Blue Boy’ Bachelor’s Button: Remarkably vibrant, sky-blue, drought-tolerant, and edible flowers.
- ‘Heavenly Blue’ Morning Glory: Prized for its truly pure blue hues and robust vining habit.
- ‘Leilani Blue’ Floss Flower: Fluffy flower heads and exceptional as cut flowers.
- ‘Blue Daze’ Evolvulus: Low-growing, never-fading blue groundcover for sun and heat.
- ‘Victoria Blue’ Salvia: Consistent spikes of rich blue that draw pollinators all summer long.
FAQs About Blue Annual Flowers
Q: Why are true blue flowers so rare in gardens?
A: Blue pigments are uncommon in nature; most “blue” flowers actually contain anthocyanins that shift color based on pH, often veering towards purple. Breeders select and hybridize to achieve the truest blue tones available.
Q: Can I grow blue annuals in containers?
A: Yes, many annuals with blue blooms, such as Lobelia, Blue Daze, and Petunia, flourish in pots with adequate sunlight, drainage, and regular feeding.
Q: How do I keep blue annuals blooming longer?
A: Routine deadheading (removing faded flowers) and providing consistent moisture and nutrients encourages prolonged blooming until frost in most annuals.
Q: Are blue annual flowers attractive to pollinators?
A: Absolutely. Bees, butterflies, and even hummingbirds are especially attracted to blue and purple blooms, making these annuals excellent pollinator plants.
Q: What pairs well with blue annuals?
A: Blue flowers combine beautifully with oranges, yellows, whites, and silvers for striking contrast and visual harmony in the garden.
References
- https://www.epicgardening.com/plant-grow-and-care-for-floss-flower/
- https://www.epicgardening.com/blue-annual-flowers/
- https://shop.epicgardening.com/products/blue-boy-bachelors-button-seeds
- https://shop.epicgardening.com/products/heavenly-blue-morning-glory-seeds
- https://www.botanicalinterests.com/community/blog/annual-flowers-seed/
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