Cosmos is a genus with many species, but the most prevalent in gardens is Cosmos bipinnatus and Cosmos sulphureus. Both are native to Mexico but bipinnatus is sometimes referred to as Mexican Aster.
It seems that bipinnatus made its way to Europe via the conquistadors in the 1500s. There’s a story floating around that it was introduced to England by the Marchioness of Bute in 1789 whose husband was the British ambassador to Spain. That’s not to say it’s not true but there isn’t much actual evidence this lady brought the seed to the UK. Which is to say…I can’t find any proof on the internet. Nonetheless, Cosmos has been a globe trotter and can be found on every continent on earth except the Arctic. Early on, after reaching Europe, it picked up the nickname “peasant’s flower” in feudal France for its ability to grow in poor soil. Cosmos hitched its way to South Africa during the Second Boar War (1899-1902) via tainted horse feed from Argentina and naturalized itself in South Korea due to botanist Woo Jang-choon creating a roadside beautifying campaign in the 1950s.
Other Interesting or Semi-Interesting Things About This Plant
The first mention of cosmos seed being sold in the US is from a seed catalog from a former debtor’s prison inmate and Scottish immigrant named Grant Thorburn in the 1830s.
C. sulphureus–Sulfur or Yellow Cosmos is considered an invasive species in some South Eastern US states.
Cosmos has been used in folk medicine and as recently as 2017 researchers in Pakistan found that sulphureus may contain hepatoprotective properties meaning it has the potential to protect the liver.
Specifications & Growing Information
- Latin: Cosmos bipinnatus, Cosmos sulphureus
- Annual that self-seeds in most zones
- Full sun/can tolerate part sun
- Stratification? No, but a chill helps germination
- Height up to 3ft.
- Germination in 7-12 days at 70F
For direct sow-Plant in a weed-free garden bed after ground temperatures have warmed. Cover seeds with around 1/4 inch of soil. In moderate climates, seeds can be planted in fall and late winter.
Tips:
- Cosmos matures late. Most blooms will come in late summer/fall in most zones.
- Deadheading spent blooms is optional but encourages more blooms.
- Mature plants sometimes need support.
- Can be started indoors.
- Works well in containers but may hinder height.
Images: © 98201 Seed All rights reserved