Some flowers are beautiful. Others are unforgettable.

Chocolate Cosmos (Cosmos atrosanguineus ‘Black Magic’) belongs to the second category. With its velvety, almost black-red flowers, elegant stems and unmistakable chocolate fragrance, it has become one of the most sought-after flowers for gardeners, flower farmers and floral designers around the world.

But what many people don’t realise is that this extraordinary flower is much easier to grow than it looks.

A flower unlike any other

At first glance, Chocolate Cosmos looks almost unreal.

Its flowers appear nearly black, but in sunlight reveal rich shades of deep burgundy, dark mahogany and velvet red. Combined with delicate foliage and long graceful stems, it creates a dramatic focal point in both gardens and bouquets.

On warm summer afternoons, another surprise appears—the flowers release a gentle fragrance reminiscent of dark chocolate.

It isn’t overpowering, but subtle, elegant and completely unique.

No wonder florists consider it one of the true luxury flowers.

Why are Chocolate Cosmos seeds more expensive?

Many gardeners notice that Chocolate Cosmos seeds cost more than ordinary cosmos varieties.

There is a good reason.

Unlike annual Cosmos bipinnatus, Cosmos atrosanguineus is a rare perennial species that naturally produces fleshy underground tubers.

Its unique colour, fragrance and relatively limited seed production make it much more exclusive.

The good news?

One packet of seeds can provide plants that you may enjoy for many years.

The secret most seed sellers never mention…

One of the biggest misconceptions online is that Chocolate Cosmos should simply be grown as an annual.

While it can certainly be enjoyed this way, something interesting happens underground.

By late summer and autumn, the plant develops tubers, very similar to those of dahlias or ranunculus.

These underground storage organs allow the plant to survive from one season to the next—provided they are protected from freezing temperatures.

Growing from seed is surprisingly easy

Many people assume Chocolate Cosmos is difficult to grow.

In reality, it germinates much like many other flowers.

Start seeds indoors 6–8 weeks before your last frost.

Use a light seed compost and cover the seeds only lightly with fine soil or vermiculite.

Germination

• Temperature: 20–22°C (68–72°F)
• Germination time: 10–21 days
• Keep evenly moist but never waterlogged.

By the time spring arrives, you’ll have strong, healthy young plants ready for the garden.

At Therapy of Flowers, we grow Chocolate Cosmos ourselves every season. One of the biggest surprises was discovering how easily the plants form healthy tubers by autumn. Since then, we lift and store them alongside our dahlias, allowing us to enjoy even stronger plants the following year.

Where to grow Chocolate Cosmos

One of the best things about this variety is its versatility.

It performs beautifully in:

• Raised beds
• Cottage gardens
• Cutting gardens
• Decorative containers
• Patio planters
• Flower boxes

Choose a sunny location with fertile, well-drained soil.

The more sunshine the plants receive, the more flowers they will produce.

A favourite among flower farmers

Chocolate Cosmos has become increasingly popular with professional flower growers.

Its elegant stems combine beautifully with:

• Dahlias
• Scabiosa
• Cosmos
• Snapdragons
• Zinnias
• Ammi majus
• Grasses
• Roses

The deep, almost black flowers create stunning contrast in both romantic pastel bouquets and dramatic autumn arrangements.

Even a single stem can completely transform a bouquet.

How to overwinter Chocolate Cosmos

This is where Chocolate Cosmos becomes truly special.

Once autumn arrives and frost approaches, treat it much like a dahlia.

Step 1

Cut the stems back.

Step 2

Carefully lift the tubers from the soil.

Step 3

Allow them to dry for several days.

Step 4

Store them somewhere frost-free throughout winter.

We store ours together with our dahlias in a cool cellar.

One of our favourite methods is placing the cleaned tubers in a ventilated box filled with dry vermiculite. Dry peat moss also works very well.

How to know your tubers survived winter

In spring, examine the stored tubers.

Healthy tubers begin to develop small growing points—often called “eyes”—just like dahlias.

Once these appear, the tubers can be divided if needed and planted again for another spectacular season.

Why gardeners fall in love with Chocolate Cosmos

✓ Flowers from summer until frost

✓ Luxurious deep burgundy-black blooms

✓ Delicious dark chocolate fragrance

✓ Excellent cut flower

✓ Easy to grow from seed

✓ Can be overwintered as tubers

✓ Perfect for premium bouquets

✓ One of the most unusual flowers you can grow

Is Chocolate Cosmos worth growing?

Absolutely.

Although the seeds cost more than ordinary cosmos, you’re not simply buying another annual flower.

You’re growing one of the world’s most distinctive ornamental plants—a flower with dramatic colour, a unique fragrance and the potential to return year after year.

If you’re looking for something truly special in your garden, Chocolate Cosmos ‘Black Magic’ deserves a place.

Why Chocolate Cosmos Is One of the World’s Most Luxurious Cut Flowers

Chocolate Cosmos isn’t just loved by gardeners—it’s also highly prized by professional florists around the world.

Its rich velvet flowers, long elegant stems and subtle dark chocolate fragrance make it one of the most desirable flowers for luxury floral design.

Because the flowers are relatively rare, have a limited growing season and produce fewer stems than many traditional cut flowers, they are often considered a premium product.

Many boutique florists describe Chocolate Cosmos as:

“Super rare. Super expensive. Super worth it.”

Luxury floral studios frequently feature Chocolate Cosmos in premium bouquets, where even a handful of stems creates an unforgettable arrangement. The deep burgundy-black flowers pair beautifully with garden roses, dahlias, Japanese anemones, scabiosa, mountain mint and ornamental grasses.

In boutique flower shops, Chocolate Cosmos is rarely sold by the bunch. Instead, florists often use just a few stems to add depth, elegance and dramatic contrast to high-end bouquets. 

 

Market example: Luxury florists such as Fox Fodder Flowers regularly feature Chocolate Cosmos in premium seasonal bouquets, illustrating the high value this remarkable flower holds in contemporary floral design.

Screenshot shown for editorial reference. Copyright remains with the original owner.

A Favourite Among Luxury Florists

Chocolate Cosmos regularly appears in the work of award-winning floral designers and luxury flower studios around the world.

Its distinctive colour, graceful stems and chocolate fragrance make it especially popular for:

• Luxury wedding bouquets
• Editorial floral photography
• Premium seasonal bouquets
• Garden-inspired floral design
• Boutique flower shops

Although considered an expensive cut flower, many florists agree that its unique beauty and fragrance make every stem worth the investment.

Grow One of the World’s Most Extraordinary Flowers

Chocolate Cosmos ‘Black Magic’ is much more than a flower. It combines dramatic velvet blooms, a delicate chocolate fragrance and the possibility of returning year after year when its tubers are overwintered correctly.

Whether you’re a flower farmer, gardener or simply someone who appreciates rare beauty, this remarkable plant will reward you with unforgettable flowers throughout summer and autumn.

If you’ve never grown Chocolate Cosmos before, this is the variety that will make you fall in love with it. 

 

Frequently Asked Questions

Does Chocolate Cosmos really smell like chocolate?

Yes. On warm sunny days, mature flowers release a delicate fragrance that many gardeners describe as dark chocolate or cocoa.

Can Chocolate Cosmos survive winter?

Yes, if the tubers are lifted before hard frost and stored in a cool frost-free location, much like dahlias.

Can Chocolate Cosmos be grown from seed?

Absolutely. Although many gardeners purchase tubers, Chocolate Cosmos is surprisingly easy to grow from seed when started indoors in early spring.

Is Chocolate Cosmos a good cut flower?

Yes. Its long stems, unique colour and subtle fragrance make it one of the most sought-after flowers for luxury bouquets.