Plant of the Week – Cosmos

Plant of the Week – Cosmos

Plant of the week - cosmos - in our garden

Cosmos bipinnatus

)ur plant of the week – Cosmos is one of my favorite garden companion plants.  I typically sow them around my garden in early spring and late summer for a burst of tall color and to attract pollinators.  The multicolor flowers are beautiful, and the tall lacy foliage makes a beautiful accent anywhere in the landscape.


Cosmos prefers full sun.  If you are doing late planting, make sure that the seeds you sow are not shaded by your other garden or landscape plantings.  Shading can be a problem when doing mid or late summer seedings. 

Plant your Cosmos to the back of your beds for the best results.  The plants will grow up to 24 inches tall, and if you plant them to the front of your beds, they will shade or mask your other plants — space or thin your cosmos to about 12 inches for best results.

Plant of the Week - Cosmos White


Cosmos are tolerant of almost any soil conditions and are drought tolerant to a certain degree.  If you are planting seeds, you can plant after the last frost and anytime after that up to late summer.  If you want to long, however, the plants may not flower before the first frost of the falls season gets to them.

Don’t plant your seeds too deep.  I like to simply scatter the seeds over the top of the bare soul and using my hand to barely cover them by running my palm over the surface of the soil. 

Cosmos Yello

Cosmos will self-seed if you let the flowers go to seed, and you can count on having cosmos in the same spot for years to come.  Be careful.  The seeds will tend to spread beyond the area where you have them planted if bare soil is available for them to take root.  Deadheading your Cosmos will prevent the inadvertent seeding and will encourage your plants to continue to put on more stems and flowers.


Cosmos are great landscape flowers.  They attract a wide variety of pollinators into the garden as well as splashes of color.  Cosmos can be had in a wide variety of colors.  There are even white varieties available.

If you are looking for cut flowers, you should have Cosmos in your cut flower garden as well.  The long, strong upright stems make Cosmos an excellent cut flower candidate.

Cosmos - CHocalate

There are more than 20 varieties of cosmos on the market, and they now exist as both annuals and perennials.  The most popular annual variety grown in the USA is Cosmos bipinnatus, which is commonly known as Mexican Aster.   A  yellow variety is available, Cosmos barely, which produces bright yellow flowers.   An interesting variety now available is Cosmos atrosanguineus, known commercially as the chocolate cosmos (more information here).  This variety of cosmos has dark, almost black flowers and has a chocolate scent.

I like to plant a variety of cosmos in my garden.  My usual practice is to make a mixture of my favorite companion plants and broadcast them among my garden plants.  I get a surprise when things start growing and flowering, which turns my garden into a colorful and interesting place and makes the space a haven for pollinators and other insects of all types.


For more information about companion planting, pollinator attractors, or flowering plants for your landscape, visit our website at West Texas Organic Gardening.

These articles from our website may be of interest if you found this article helpful.

Companion Planting Reference

Fall Planting Guide

Fall Landscape Tips

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