blue green cactus
blue green cactus
(Image credit: Fabio Ticozzi)

In the cactus world, there is a diverse variety of sizes, forms, and colors. Blue varieties of cactus are not as common as green, but they do occur and offer a unique opportunity to bring in a tone that really has an impact on the landscape or even dish gardens.

Growing Cactus That is Blue

Feeling blue? Then try growing blue cacti. The sharp hue of these plants creates drama in the garden. There are many blue cactus types that offer some interesting difference of color combined with diverse forms and brilliant flowers.

Why are some cactus blue? The thought is that it is some sort of adaptation the plant has developed. Cactus plants are among the most adaptive plants known and have evolved all sorts of interesting coping mechanisms to survive in harsh environments. Blue tones may have evolved to protect the plant from sun or help deter certain pests. No one knows for sure exactly, but the color is not often found in nature and provides the gardener an opportunity for some astounding color combinations.

Blue Varieties of Cactus

If you want to try growing blue cacti, the challenge is to find one that suits your needs. There are big blue cactus types for the garden and smaller species that are better suited to indoor containers. Most blue cactus are desert varieties, meaning they should be outdoors only in southern regions or used as indoor plants for northern gardeners.

Some large types include:

  • Pachycereus Elephant cactus – The ribs of many Pachycerus cacti are blue-green in color.
  • Cholla cactusCholla cactus, like the chain fruit cholla, is grown in the south and southwest United States, and is a fuzzy blue.
  • Opuntia – Some varieties of Opuntia cactus have distinctly blue skin leaning to a purple blue.
  • Cereus Column cactus – Column cactus has an upright growth and definite blue skin.
  • Pilosocereus – A Brazilian species, Pilosocereus, also known as tree cactus, is really powder blue!

If you want to grow an indoor cactus that is blue, you could choose from these options:

  • Agave – A classic that comes in various sizes, agave is noted for its rosette form.
  • Bishop's CapBishop's cap is a small chunky cactus with no discernible stems in a five-point star form.

Since indoor cacti are bred with numerous interesting traits to draw in consumers, blue varieties in smaller plants are not as rare and are actually too numerous to mention. Go to your nearest home improvement or garden store and you will find many standard and grafted types from which to choose.

Notes on Blue Cacti

Many of the bluest varieties come from Brazil. They are among the most cold sensitive varieties. They love extreme heat and full, blazing sun. Always make sure the soil they are planted in is a bit gritty and drains well.

These cacti types don't need excessive nutrients in the soil and are easy to manage, with minimal water requirements. The blue notes really stand out among your regular green plants and draw the eye to such colorful specimens.

Bonnie L. Grant

Bonnie Grant is a professional landscaper with a Certification in Urban Gardening. She has been gardening and writing for 15 years. A former professional chef, she has a passion for edible landscaping.