The Chocolate Cosmos (Cosmos Atrosanguineus) Care Guide

The Chocolate Cosmos, otherwise known as the Cosmos Atrosanguineus or Bearberry Cotoneaster, Cotoneaster humifusa, Cotoneaster humifusus, is a rather well known shrub plant by gardening enthusiasts around the world.

Best known for its low maintenance and fast growth, this shrub will likely liven up your house (or garden) with its dark green colored leaves. But, only if you learn how to take proper care of it for it to thrive.

Fortunately, taking care of your Chocolate Cosmos is not too difficult – as long as you follow our guidelines in this Chocolate Cosmos Care Guide. Now let’s get started.

In order to take proper care of your Chocolate Cosmos you’ll need to keep in mind the following guidelines:

  • Water: The Chocolate Cosmos needs evenly spread moist soil – try to avoid letting the soil dry out.
  • Light: Keep your Cosmos Atrosanguineus in an environment where it can receive full sun on a daily basis. 
  • Soil: Make sure to keep the Chocolate Cosmos in soil with well-draining properties, so ideally, one that is made of clay, loam, chalk, and sand.

And as with many other plants, these are the only three care factors you need to remember to make sure your Chocolate Cosmos is, for the most part, healthy and well to survive.

Chocolate Cosmos flower

Scientific / Botanical Aspects

In botanical terms, the Chocolate Cosmos belongs to the Rosaceae family, the genus Cotoneaster and the species Dammeri, hence its scientific (or botanical) name Cosmos Atrosanguineus.

Other common Rosaceae species include Berri-Magic® Japanese Skimmia, Rosa X ‘Radyod’ Plant Patent #14700, Brilliant Red Chokeberry, Rosa X ‘Cecile, Frosty® Potentilla, Forsythia X ‘Courtasol’, Prunus Serrulata ‘Kwanzan’, Red Delicious Apple, Prunus X ‘Snofozam’, Yellow Lady Banks Climbing Rose, Breath of Spring Spirea, Darkstar® Purple Leaf Sand Cherry, Gingersnap™ Potentilla, Malus X Domestica ‘Golden Delicious’, Wall Cotoneaster, Malus ‘Braeburn’, Malus Domestica, Flowering Quince, Pink Stripe New Zealand Flax, Potentilla Fruticosa ‘Gold Star’, Prunus Cerasifera ‘Krauter Vesuvius’, Prunus Cerasifera ‘Thundercloud’, Prunus Persica Var. Nucipersica ‘Snow Queen’, Floribunda rose ‘Golden Beauty’, Climbing Rose ‘Golden Showers’, Climbing Rose ‘Joseph’s Coat’, Large-Flowered Climber, Spiraea Japonica ‘Conspiyet’, Alchemilla Mollis ‘Thriller’, Prunus Subhirtella ‘Pendula’, First Snow Spirea, Fuji Apple, Japanese Rose, Versailles Laurel, Prunus Salicina ‘Ozark Premier’, Alyssum Serpyllifolium, Red Chokeberry ‘Brilliantissima’ and Badja Peak Mint Bush.

As with other Cotoneaster’s, the Chocolate Cosmos is a herbaceous plant, which means it will die back to the ground every year. 

Growing Region

The Chocolate Cosmos is a plant native to the Tibet to Central China.

As a rule of thumb, we recommend to always keep in mind your plants’ native region and environment, since these are the conditions that your Chocolate Cosmos is most accustomed to, thus where it can most favorably.

With this in mind, the Cosmos Atrosanguineus will be most used to the heat zones in the 7 – 8 region, as the plant hardiness level falls between 5b, 5a, 6b, 6a, 7b, 7a, 8b, 8a and the ideal climate zone is between 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.

Growth and Size


In terms of size and growth, the Chocolate Cosmos is a relatively fast grower, which makes things tricky for any plant enthusiast.


But, what size of Chocolate Cosmos are we talking about? What can you expect in terms of height, spread and spacing? Let’s dig in…

The Cosmos Atrosanguineus can grow up to 9″ – 1′ (22cm – 30cm) in 9″ – 1′ (22cm – 30cm) and 4′ – 6′ (120cm – 180cm) in 4′ – 6′ (120cm – 180cm). 

These dimensions make the Chocolate Cosmos a relatively large shrub compared to others, so it’s best to keep this fact in mind since it will affect where you want to keep yours at home.

This is why experts recommend keeping an area of approximately 48″ – 72″ (120cm – 180cm) free so the Chocolate Cosmos can spread to its best extent.


In terms of watering, the Chocolate Cosmos is a fairly complicated plant to take care of.

This is mostly because it has a not so straightforward watering schedule and somewhat irregular watering needs.

Specifically, most experts agree that the Cosmos Atrosanguineus needs evenly spread moist soil – try to avoid letting the soil dry out.

Which is why it is considered a plant with relatively low to average needs in terms of water. 

Chocolate Cosmos up close


As a rule of thumb, you should remember to keep your Chocolate Cosmos in soil with well-draining characteristics, as these will guarantee the right conditions for your plant to grow and thrive. 

When you consider this, this is why you should aim to choose soil that has good drainage, and moist properties to keep the right moisture levels at all times. 

In our experience, the famous ‘thumb’ or ‘finger’ test is what works best for the Chocolate Cosmos since with it, you will be able to give it the right amount of water, every time – regardless of the environment or placement where you do decide to keep it.

Soil Mix

As mentioned earlier, the Chocolate Cosmos prefers to have soil with good drainage, and moist properties at all times, reason why you need to make the soil mix out of clay, loam, chalk, and sand.

This is why most experts agree that the Chocolate Cosmos requires soil with loam (silt), which will give you the right conditions it needs.

In addition to this, expert gardeners recommend having preferably alkaline, acid or neutral soil.

Light and Exposure

In terms of light & exposure, the Chocolate Cosmos requires full sun in order for it to thrive under the right conditions. 

Most experts agree that this shrub will do well as long as you keep it in partial to full sun, and it will be able to grow properly.

Specifically, we recommend that you place your Cosmos Atrosanguineus in little to partial shade (only 2-6 hours of direct sunlight a day), to full and direct sun (more 6 hours of direct sunlight per day).


Being a herbaceous plant, the Chocolate Cosmos will die back to the ground every year. 

But, you can expect it to have its ‘prime-time’ during the spring (early, mid, late), the summer (early, mid, late), the fall, and during the winter.


You can expect your Chocolate Cosmos to flower around the spring and in the summer months from April to June (spring), and from July to September (summer).

In particular, this shrub is well known for its fragrant, flowers for cutting and showy flowers around the plant enthusiast community.

The Chocolate Cosmos produces some beautiful purple, or white flowers around this time of year.


The leaves from the Chocolate Cosmos have a beautiful dark green color during most of the year.

In particular, they have a simple arrangement with a alternate organization in its leaves.

You can expect the leaves from your Cosmos Atrosanguineus to be around (1-3 inches) in size.

Chocolate Cosmos and bees

Attracts, Tolerance and Resistance

The Chocolate Cosmos is well known for being able to attract butterflies and birds, so keep that in mind when choosing your plant, as you’ll likely end up finding one or another in your garden.

Additionally, it has a special tolerance for drought conditions, so don’t worry if any of these come along, your Cosmos Atrosanguineus will be fine.


Does your Chocolate Cosmos have any garden recommendations? Does it serve any gardening purposes? Here’s how you can get the most out of your new plant.

Most Cosmos Atrosanguineus owners agree that this shrub will look great in most cottage, contemporary and rustic gardens of all types. 

Other owners consider that they complement well most gardens of gravel and rock garden, and in informal and cottage styles. 

In particular, the Chocolate Cosmos’s best location within your garden is in edging, banks and slopes, and in ground covers, others use it for landscaping in a container, border, or a cutting garden.

Companion Plants

Chocolate Cosmos’s do well with some other plants beside it. One good companion plant is the Coreopsis auriculata, which will pair up nicely with your leafy friend.

Others consider that a nice Verbascum will work well too, so choose whichever you find works best for you!


Even though we covered a lot of care information for your Chocolate Cosmos, remember the basics: sunlight, soil and water, as these should be enough to grow a healthy plant at home.

Martin Duran

Hey y'all! My name is Martin Duran and I am from Cali, Colombia. Since 2018 I have been learning about plants and how to take care of them. Here's is my journey... “The clearest way into the Universe is through a forest wilderness.” ― John Muir

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