Plant Care Black Cosmos

Black Cosmos

4.0 out of 5 (2 experiences)

Black Cosmos has a Fast grower plant personality Fast grower
Black Cosmos has a Survivor plant personality Survivor

Also known as

Chocolate Cosmos, Chocolate Cosmos and Black Dahlia


Cosmos atrosanguineus

How to care for Black Cosmos


How often to water your Black Cosmos

Water needs for Black Cosmos
0.5 cups
every 9

Black Cosmos needs 0.5 cups of water every 9 when it doesn’t get direct sunlight and is potted in a 5" pot.

Use our water calculator to personalize watering recommendations to your environment or download Greg for more advanced recommendations for all of your plants.

Calculate water needs of Black Cosmos

Water 0.5 cups every

Does your plant get direct sunlight?

Select the pot size


Check the growing potential in your area

A plant's growing potential is determined from its location, the time of year, and current local weather.

Select a city to check sunlight intensity

Finding light for Chocolate Cosmos in your home

Light needs and placement for plant Black Cosmos: 1ft from a window
1ft or less from
a window

Black Cosmos love being close to bright, sunny windows 😎.

Place it less than 1ft from a south-facing window to maximize the potential for growth.

Black Cosmos does not tolerate low-light 🚫.

Select your region to see how the current weather in your area affects the placement of Black Cosmos in your home 🏡.


How to fertilize Black Cosmos

Nutrient, fertilizer, and repotting needs for Black Cosmos: repot after 2X growth

Most potting soils come with ample nutrients which plants use to produce new growth.

By the time your plant has depleted the nutrients in its soil it’s likely grown enough to need a larger pot anyway.

To replenish this plant's nutrients, repot your Black Cosmos after it doubles in size or once a year—whichever comes first.

Difficulty Level

Black Cosmos is generally easy to care for, though some plant parents report facing challenges with growing it. Check out the reviews down below to read more about their experiences!

Water Needs
Sunlight Needs
Growing Outdoors

Care Summary for Black Cosmos

Black Cosmos

Black Cosmos

Greg recommends:


0.5 cups every 9 days


< 1ft from a window


Repot after 2x growth

Based on the 4” pot your plant is in, and that it doesn’t get direct sunlight.

What other plant parents say

Black Cosmos has a Fast grower plant personality Fast grower 2
Black Cosmos has a Survivor plant personality Survivor 1
Black Cosmos has a Blooms easily plant personality Blooms easily 1
Mayamochii avatar
leaf-1 9 Plants
xp 274 XP
globe Oakland, California

if you think it’s dead, it’s probably not. just trim back the dry foliage and it’ll come back!

Fast grower Fast grower
Survivor Survivor
Melissa avatar
leaf-1 2 Plants
xp 122 XP
globe Windsor, California

Give it room to grow! It blooms every day

Fast grower Fast grower
Blooms easily Blooms easily

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