Arizona native cotton is a lovely shrub to small tree – and a relative of cultivated cotton. It has been brought into the native plant trade in parts of the Southwest as a low water plant.

Cover image: Native cotton in bloom.  Note the tiny pink spots on the petals.

The Name of this Native Cotton

Arizona native cotton goes by many names. The scientific name is Gossypium thurberi. It is also known as Arizona wild cotton, Thurber’s cotton, desert cotton, and in Spanish as algodoncillo or little cotton.

The cotton family is called the Malvaceae, also called the mallow or hibiscus family. Unlike many members of the family, individual flowers of the wild cotton are not large and showy. The small flowers come in colors of creamy white to yellow with a hint of pink to bright crimson spots on the petals. Small in size, when the shrub is in bloom – the overall effect can be quite striking. The flowers  also have a mild sweet fragrance and the native stingless bees adore them.  For showy flowers, grow the cousin Hibiscus.

Native Cotton

While cultivated cotton is treated as an annual, it is technically a perennial shrub. More about commercial cotton at the tail end of this article.

Native desert cotton is also a perennial shrub. It grows into a pretty somewhat vase-shaped shrub or maybe even a small tree that reaches 8 to 12 feet tall.  Landscaper designers call the leaves “medium textured.” This means they are not tiny like a palo verde, nor giant like a sycamore.  The leaf shape is termed “palmately lobed.”  The leaves have five fingers – like the palm of your hand.

Those leaves will vary in size with the amount of water the plant receives. Leaves on wild plants are generally 2 to 3 inches across but in the landscape, they can be 5 inches across and form a dense screening shrub with a eye-pleasing emerald green hue. But don’t plant the native cotton as a screen to hide the neighbors junk heap, because it is deciduous. All those lovely emerald leaves turn even lovelier shades of red, maroon, even almost purple in autumn.  And then they fall.  They do leave a lovely sculptured form, but it won’t screen much.  Due to this deciduous nature, it is best planted as a background shrub, not as a focal point.

Deciduous? Are they Messy?

While desert cotton does drop it’s leaves, it is not what we plant people would call “messy.”

The flowers develop into small dark brown pods called bolls. These are less than an inch around and fairly fragile, breaking apart and blowing away. Despite my personal desire for more of these lovely plants, they did not reseed extensively around the yard. This could be a plus for most homeowners.

The tiny bits of bolls could be an issue in yards with pools, but are not a problem in a natural landscape.  The leaf litter caused by the autumn leaves is confined to about a three week window, so again, not much of a problem.

Those Leaves

I love the rich emerald green color in spring and summer, and the autumn color is fantastic – but.  The “but” is the palmately lobed leaves.  They can lead to mistaken identity.

At one former home, I pruned desert cotton up into a single-trunked tree, and it never failed to have a parade of neighbors stopping by in autumn, some exclaiming over my ability to grow “Japanese maple.”  For anyone that desires autumn color, Thurber’s native cotton is an excellent choice.

At a different former home, the neighbors peeked over the fence, saw the plant, and called the cops on me. They claimed I was growing some of that wacky weed. I guess the leaves are similar (but how did they know?!)  Anyway, after an interesting chat with some very polite DEA agents, and confirmation from their dog, I was left to grow my desert native cotton in peace.

Grow Native Cotton

Let’s look at the four elements of gardening to give you some tips on growing this lovely plant.

Earth (Soil)

When it comes to planting desert cotton, consider that it is usually found growing on rocky slopes, in canyons, and now along road side ditches. It is found from the Superstition Mountains of Arizona, from there south and east into Mexico and Texas. Although in the wild it is generally found in well-drained soils, my cottons have all done very well in clay soil with infrequent water. And they don’t mind caliche at all!

Air (Temperature)

When it comes to cold hardiness, the desert cotton is dormant in winter and survived the killer freeze of 2011, the same freeze that hit 11F at my home and killed my Ten-Degree tangerine tree.

Although the desert cotton plants are not found in the wild in Nevada or northern New Mexico, this may be due to rainfall rather than the cold temperatures.

Fire (Sunlight)

Full sun to full shade. I even grew them along a west facing block wall. I currently have some growing in fairly dense shade under a mesquite tree. They flower less than those in more sun.

Water

Remember the native to canyons bit? Well they do like some extra water. This means the native cotton is not for a yard that doesn’t get some irrigation.  (Yes, that’s a double negative.)  It will require irrigation.  About the same amount of water as the Texas rangers or Texas rain sage, but it has those lush, emerald green leaves.  This means that eyes used to back East green find very native cotton very appealing in the landscape.

Wildlife

As for wildlife, desert cotton does not appear to be browsed by rabbits or javelina. It is a larval food plant for the Arizona royal moth (Citheronia splendens sinaloensis) and appears to be pollinated by the solitary desert bees.

Back in the 1930’s attempts were made to eradicate this wild native cotton from the mountains and foothills of southern Arizona. It was believed that the weevil found feeding within the wild bolls was the infamous cotton boll weevil that was a huge problem for the cotton industry.  Taxonomic studies by an entomologist determined that the weevil was a new species to science and he promptly named the Thurber weevil because it was found in Gossypium thurberi.  This species is not the same as the cotton weevil and furthermore, the Thurber weevil did not affect cultivated cotton. Luckily the eradication efforts failed and the plant has since returned to be a fairly common, attractive native plant.

Grow Plants or from Seeds

I have successfully grown the species from seeds I found while hiking. If you don’t hike remote canyons, there are a few local, specialty nurseries currently sell desert cotton, generally in one or five gallon sizes. It can also be found on-line with named cultivars. This charming desert native certainly deserves a second look for low-water landscape use across the Southwest.

Appendix

The Five ‘C’s”

If you grew up in Arizona in the 1960’s and 70’s you learned that the state is renowned for “The Five C’s.”  You could use your five fingers and count them off.  Climate, Cotton, Citrus, Cattle, and Copper.  Since then, over ten million people have moved into the Southwestern for the first C – the Climate.  Now the once extensive cotton fields, citrus groves, and cattle ranches are mostly just a part of our history.  At least we still have this lovely species of native cotton to grow in our yards.

About Other Cotton Species

There are 55 recognized species of cotton, but not all of them have the long fibers used to create cotton cloth. The cotton grown and harvested for cotton cloth comes from four species that were domesticated in antiquity.

Gossypium hirsutum – Mexican cotton or upland cotton is originally native to Arizona, Mexico, Central America, the Caribbean, and southern Florida. About 90 percent of world production comes from this species and hybrids of it.

Gossypium barbadense – known as extra-long staple cotton, is native to tropical South America. Over 5 percent of world production comes from this species.

Gossypium arboreum – tree cotton, is native to India and Pakistan and is used for less than 2 percent of world cotton.

Gossypium herbaceum – Levant cotton, originally native to southern Africa was carried in ancient times to Egypt, Israel, and the Arabian Peninsula.  It accounts for less than than 2 percent of world production of cotton.

Colors of Cotton

Cotton fibers occur naturally in colors of white, brown, tan, golden, pink, and green.  Modern day fears of contaminating the genetics of white cotton have led many cotton-growing locations to ban the growing of colored cotton varieties.

Over a decade ago, a small production company was trying to introduce these naturally colored undyed cottons for babies and other people with sensitive skin. Sadly, they were forced out of business by these laws. Before they were gone I scored several skeins of this wonderful cotton and knit up some lovely items for myself and others.

Butterfly Plant Book – For AZ, NV, NM

Because native cotton is a host plant for lepidoptera – consider how to grow other butterfly plants with my book Butterfly Gardening in Southern Arizona, Revised Edition.

It says “southern Arizona” because I am nerdily precise, and when I first wrote it I had not done enough research on other parts of the Southwest.  I now know that the plants discussed in this handy guide  will grow in Southern Nevada, Eastern California, Across the deserts of Arizona, into Southern New Mexico, and through Big Bend into the Texas Hill Country.

Published by locally by Tierra del Sol Institute – whose mission statement is “Helping people live in harmony with their environment.”   All the profits from the sale of the book go to their Horticulture Therapy programs.

Note.  This slender volume was printed in Tucson by Arizona Litographers, the first ever printing press in America to be run entirely on green energy.  They have won awards for their efforts to reduce impact upon the earth, and thus fit well with the Tierra del Sol mission to help people live more lightly on this earth.

Legal

© Article copyright Jacqueline A. Soule. All rights reserved. You must ask permission to republish an entire blog post or article. Okay to use a short excerpt but you must give proper credit. You must also include a link to the original post on my site. No stealing photos.