Customer Service Hours
Mon-Fri 8-4 MST
Features
Family
Asteraceae
Native
Mexico
Life Cycle
Annual
Plant Height
Tall (Greater than 24")
Flower Color
Orange
Bloom Season
Summer to frost
Further Information
Plant Characteristics
- Attracts Butterflies
- Attracts Hummingbirds
- Attracts Pollinators
- Cut Flower
Growing Conditions
Drought Tolerant
About Diablo Cosmos Seeds
Cosmos sulphureus
1–1½" bright, scarlet/orange blossoms
Planting Cosmos
Plant Spacing
A group of 3 seeds every 12"
Light Required
Full sun
Plant Height
Tall (Greater than 24")
Planting Depth
Barely cover
Planting Details
| Seed Depth | Barely cover |
|---|---|
| Seed Spacing | A group of 3 seeds every 12" |
| Thinning | When 1" – 2" tall, thin to 1 every 12" |
| Germination | 5–10 days |
| Start Indoors | 4 to 6 weeks before your average last frost date. |
| Direct Sow | RECOMMENDED. 1 to 2 weeks after your average last frost date, and when soil temperature is at least 60°F. |
| Growing & Harvesting | For longest vase life, cut stems just as flower buds begin to open. |
Find Your Frost Date & Grow Zone
Average First Frost Date
October 19
Average Last Frost Date
May 19
Your Hardiness Zone is
5b
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Rating
Which best describes you as a gardener?
32 reviews
- Cathleen M.Verified BuyerRated 5 out of 5 stars9/10/26Trusty bloomers
I love being able to plant seeds late in the season and know they will flower. These seeds do just that. They're beautiful in the garden!
Which best describes you as a gardener? IntermediateBIBotanical Interests9/13/26Hey Cathleen,
We're so happy to hear that your Diablo Cosmos Seeds are such trusty bloomers! It's awesome that you can plant them late in the season and still get those beautiful flowers in your garden - that's exactly the kind of reliable performance we love to see! Thanks so much for being part of the growing community! Keep on growing 🌻
- Beth R.Verified BuyerRated 5 out of 5 stars8/21/26Grew fast and self-seeded!
Love these cosmos. The leaves are different the traditional cosmos, love the look. But the colors are so pretty and they grew fast! They outperformed the other cosmos I planted by a mile. I found a Monarch butterfly on them the other day too! Will definitely purchase again.
Which best describes you as a gardener? IntermediateBIBotanical Interests8/28/26Hey Beth,
We're so stoked to hear that your Diablo Cosmos have been such a fantastic success! It's awesome that you're loving those unique leaves and the gorgeous colors, and we're really impressed that they grew so fast and outperformed your other cosmos by a mile. Plus, attracting a Monarch butterfly? That's the cherry on top! Thanks so much for being part of the growing community! Keep on growing 🌻
- Denise W.Verified BuyerRated 5 out of 5 stars6/19/26Bushy & Colorful
Beautiful bright colors! Tall and Whimsical! They grew fast!
Which best describes you as a gardener? IntermediateBIBotanical Interests6/24/26Hey Denise,
We're so thrilled to hear about your amazing Diablo Cosmos success! It sounds like they really delivered with those beautiful bright colors and that tall, whimsical growth you got! Fast-growing cosmos are always so exciting to watch as they shoot up and start showing off those gorgeous blooms. There's something so magical about cosmos swaying in the garden with all that vibrant color! Thanks for sharing your fantastic Diablo Cosmos experience with us! Keep on growing 🌻️
- TabithaRated 5 out of 5 stars6/12/265 Stars
Always pleased
- Rebecca B.Verified BuyerRated 5 out of 5 stars6/3/26Quick to sprout!
Three days to sprout in north Texas's wild temp extremes. Planting late so I hope they can cope with our summer
Which best describes you as a gardener? IntermediateBIBotanical Interests6/3/26Hey Rebecca,
Wow, three days to sprout in those crazy north Texas temperature swings - that's incredible! Your Diablo Cosmos Seeds are already showing they're tough little fighters. We're confident they'll handle your summer heat like champs since cosmos are such resilient bloomers. Even with the late planting, you should have some gorgeous fiery blooms to look forward to! Thanks for sharing your speedy Diablo Cosmos germination success with us! Keep on growing 🌻️