Ashley Scott shares 20 flowers starting with C—Cosmos, Clematis, Carnation, more—for vibrant gardens. Easy US growing tips!
Hey garden friends! I’m Ashley Scott, and after a decade of growing plants in my California backyard, I’m excited to share 20 flowers that start with C to bring vibrant beauty to your garden beds. From the classic Cosmos to the elegant Clematis, these blooms offer diverse colors, shapes, and pollinator appeal for US gardeners in zones 3-10. I’ve had my share of successes (and a few pest battles!), so I’m packing this guide with practical tips, personal stories, and specific advice to help you grow these stunners. Let’s make your garden shine!
Why Grow Flowers That Start with C?
These flowers add texture, fragrance, and wildlife to your garden beds. They suit various styles—cottage, modern, or wildflower—and thrive in well-drained soil with compost. My Cosmos patch turned a plain corner into a butterfly haven last summer. Whether you’re in a chilly Midwest plot or a sunny Southwest one, these flowers offer long blooms, low care, or pest resistance. For general flower tips, check our flower gardening guide on USA Garden Hub.
1. Cosmos
Cosmos bloom summer to frost with airy flowers. My ‘Sensation Mix’ drew butterflies for 10 weeks.
- Grow It: Sow seeds in spring, 12 inches apart, in full sun with average soil (pH 6.0-7.0).
- Care: Water 1 inch weekly; deadhead for more blooms.
- Tip: Use in wildflower beds; self-seeds easily.
- Zones: 2-11 (annual).
Resource: The Old Farmer’s Almanac on cosmos care.
2. Clematis
Clematis blooms spring to summer with star-shaped flowers. My ‘Jackmanii’ climbed 8 feet in a season.
- Grow It: Plant in spring, 3 feet apart, in full sun with roots in shade and rich soil.
- Care: Water 1 inch weekly; prune after bloom based on variety.
- Tip: Train on arbors for vertical drama.
- Zones: 4-9.
Resource: Cornell University on clematis.
3. Carnation (Dianthus)
Carnations offer spicy-scented blooms from spring to summer. My ‘Grenadin’ lasted 6 weeks.
- Grow It: Plant in spring, 12 inches apart, in full sun with well-drained soil (pH 6.0-7.0).
- Care: Water 1 inch weekly; deadhead for rebloom.
- Tip: Use in borders or containers.
- Zones: 5-9.
4. Coreopsis (Tickseed)
Coreopsis blooms summer to fall with daisy-like flowers. My ‘Sunburst’ attracted bees galore.
- Grow It: Plant in spring, 12 inches apart, in full sun with average soil.
- Care: Water 1 inch weekly; divide every 3 years.
- Tip: Great for pollinator gardens.
- Zones: 3-9.
Resource: University of Minnesota on coreopsis.
5. Chrysanthemum
Chrysanthemums bloom in fall with vibrant colors. My ‘Sheffield Pink’ lasted 6 weeks.
- Grow It: Plant in spring, 18 inches apart, in full sun with rich soil.
- Care: Water 1 inch weekly; pinch until July for bushiness.
- Tip: Use for fall displays.
- Zones: 5-9.
6. Calendula
Calendula blooms spring to frost, edible petals. My ‘Pacific Beauty’ self-seeded.
- Grow It: Sow seeds in spring, 6 inches apart, in full sun with average soil.
- Care: Water 1 inch weekly; deadhead.
- Tip: Use in herb gardens or salads.
- Zones: 3-10 (annual).
7. Camellia
Camellia bloom winter to spring with lush flowers. My ‘Winter Star’ bloomed in February.
- Grow It: Plant in fall, 4 feet apart, in partial shade with acidic soil (pH 5.5-6.5).
- Care: Water 1 inch weekly; mulch roots.
- Tip: Use in shrub borders.
- Zones: 7-9.
Resource: Purdue Extension on camellias.
8. Celosia (Cockscomb)
Celosia blooms summer to frost with feathery heads. My ‘Flamingo Feather’ was vibrant.
- Grow It: Sow seeds in spring, 8 inches apart, in full sun with rich soil.
- Care: Water 1 inch weekly; avoid wet foliage.
- Tip: Use in bright borders.
- Zones: 2-11 (annual).
9. Columbine (Aquilegia)
Columbine blooms in spring with spurred flowers. My ‘McKana’ self-seeded beautifully.
- Grow It: Sow seeds in fall, 12 inches apart, in partial shade with rich soil.
- Care: Water 1 inch weekly; let self-seed.
- Tip: Use in woodland gardens.
- Zones: 3-9.
10. Cornflower (Centaurea)
Cornflowers bloom summer with blue flowers. My ‘Blue Boy’ was a cutting garden star.
- Grow It: Sow seeds in spring, 6 inches apart, in full sun with average soil.
- Care: Water 0.5 inch weekly; deadhead.
- Tip: Use for cut flowers.
- Zones: 3-8 (annual).
11. Crocus
Crocus blooms in early spring, often through snow. My ‘Ruby Giant’ popped up in March.
- Grow It: Plant bulbs in fall, 3 inches deep, in full sun with well-drained soil.
- Care: Water 0.5 inch weekly in spring.
- Tip: Plant in groups of 20 for impact.
- Zones: 3-8.
12. Cyclamen
Cyclamen blooms fall to winter with nodding flowers. My ‘Persicum’ thrived in shade.
- Grow It: Plant tubers in fall, 2 inches deep, in partial shade with rich soil.
- Care: Water 1 inch weekly; keep dry in summer.
- Tip: Use in shade gardens.
- Zones: 5-9.
13. Cleome (Spider Flower)
Cleome blooms summer to frost with spidery flowers. My ‘Senorita Rosalita’ was thornless.
- Grow It: Sow seeds in spring, 18 inches apart, in full sun with average soil.
- Care: Water 1 inch weekly; self-seeds.
- Tip: Use for tall borders.
- Zones: 3-11 (annual).
14. Canna Lily
Canna Lilies bloom summer with bold flowers. My ‘Tropicana’ reached 5 feet.
- Grow It: Plant rhizomes in spring, 2 feet apart, in full sun with rich soil.
- Care: Water 1 inch weekly; lift rhizomes in Zone 5.
- Tip: Use for tropical flair.
- Zones: 7-10 (lift in colder zones).
15. Catmint (Nepeta)
Catmint blooms summer with lavender spikes. My ‘Walker’s Low’ drew bees.
- Grow It: Plant in spring, 18 inches apart, in full sun with average soil.
- Care: Water 1 inch weekly; shear after bloom.
- Tip: Use in borders; cat-friendly.
- Zones: 4-8.
16. Coneflower (Echinacea)
Coneflowers bloom summer to fall, drought-tolerant. My ‘Purple’ was a butterfly magnet.
- Grow It: Plant in spring, 18 inches apart, in full sun with average soil.
- Care: Water 1 inch weekly; divide every 4 years.
- Tip: Use in native gardens.
- Zones: 3-9.
17. Clarkia
Clarkia blooms summer with delicate flowers. My ‘Godetia’ self-seeded.
- Grow It: Sow seeds in fall, 6 inches apart, in full sun with average soil.
- Care: Water 0.5 inch weekly; deadhead.
- Tip: Use in wildflower mixes.
- Zones: 3-10 (annual).
18. Candytuft (Iberis)
Candytuft blooms spring with low clusters. My ‘Snowflake’ edged a path.
- Grow It: Plant in spring, 8 inches apart, in full sun with well-drained soil.
- Care: Water 1 inch weekly; shear after bloom.
- Tip: Use in rock gardens.
- Zones: 3-8.
19. Cranesbill (Geranium)
Cranesbill blooms spring to summer, low-growing. My ‘Rozanne’ spread fast.
- Grow It: Plant in spring, 12 inches apart, in partial shade with rich soil.
- Care: Water 1 inch weekly; divide every 3 years.
- Tip: Use as ground cover.
- Zones: 4-8.
20. Calceolaria (Slipper Flower)
Image Prompt: A garden bed with yellow Calceolaria pouch-like blooms. Show a gardener planting, with soil and a cool spring backdrop.
Calceolaria blooms spring with pouch flowers. My ‘Pocketbook’ was a pot star.
- Grow It: Plant in spring, 8 inches apart, in partial shade with rich soil.
- Care: Water 1 inch weekly; keep cool.
- Tip: Use in containers.
- Zones: 9-11 (annual elsewhere).
Mistakes to Avoid
I’ve goofed up; don’t you:
- Overwatering Crocus or Carnation; soggy soil rots roots.
- Not pruning Clematis; wrong cuts reduce blooms.
- Skipping compost; weak soil cuts flowers.
Check our common gardening mistakes for more.
Make Your Garden Glow with These C-Flowers
These 20 flowers that start with C bring color, fragrance, and pollinators to your garden beds. From Cosmos’ airy blooms to Clematis’ climbing vines, plant in well-drained soil, add compost, and follow my tips for a stunning display. Which one’s going in your garden? Share in the comments; I’d love to hear! For more ideas, visit our full gardening blog or sustainable gardening tips on USA Garden Hub. Happy planting!
