Spines have always been associated with cacti. They are highly modified stems that protect these plants from animals that want to feed on them. They also prevent them from losing too much moisture in their extremely hot natural growing environment.
But as plants were cultivated for ornamental and agricultural purposes, the spines have become less prominent, almost non-existent in some cacti like the varieties and hybrids of Opuntia.
What Is A Spineless Cactus?
There are many cactus species that do not have noticeable spines like Lophophora and Astrophytum but the term Spineless Cactus generally refers to some varieties and hybrids of Opuntia with scientific names such as O. boldinghii, O. gosseliniana, and O. nuda.
Commonly called Spineless Prickly Pear Cactus, flat cactus and thornless cactus, Opuntia species have distinct branching pad-like stems dotted with glochids (barbed bristles) and sharp spines. The fruit borne looks like a pear, only speckled with prickles hence the name.
In the early 1900s, the notable plant breeder Luther Burbank developed hybrids by crossing and cultivating O. ficus-indica and O. tuna which were intended as a means to provide food and create better cactus blooms (1).
Over 60 varieties were produced and all of them were spineless which eventually popularized this genus of cacti and the name Spineless Cactus.
Why Are These Cacti Spineless?
Spineless Opuntia cacti were developed primarily for their “thalli” or edible stems which were used as feed resources for livestock. A xerophyte that thrives in dry, arid conditions, Spineless Cacti provided food without the added labor of removing the hard spines to make it safe for consumption (2).
Aside from the fruit of some varieties, their pads are also edible and are widely used in different cuisines in Mexico, California, and Texas. And because of its ease of propagation and adaptive growth, the spineless prickly pear became a popular ornamental plant too. Through late spring and summer, the pad-like stems bear 3 to 4 inches of striking flowers that come in yellow, orange, pink, and red, depending on the variety (3).
Native to the arid regions of the US, Mexico, and South America, these Opuntia cacti thrive in sunny areas. Well-drained sandy loam is preferred to retain just the right moisture for their growth. They are drought-tolerant plants so watering can be sparse.
Since the plant is mostly flat stems facing a uniform direction, it may benefit from stake support or protection from extreme windy conditions as well as the cold winter winds. A balanced fertilizer during the spring season will help keep the plant healthy, and if Spineless cacti were grown for their edible pad, a high-nitrogen fertilizer is recommended (3).
Propagation and Care
An Opuntia cactus can be grown from seeds planted in garden beds. A full-grown plant requires full sun but growing from seeds requires shade. This method may be easy but takes years to produce a plant.
Taking stem cuttings is preferable as long as they come from pads that are no younger than 6 months old. The cuttings should be allowed to form callous in a week or two in a well-ventilated area to avoid rotting or fungal infection.
Once calloused, they can be planted in a potting mix of equal parts soil and sand or pumice. Rock support on either side of the cuttings will help stabilize the plant and form roots better. A full-grown plant can have stems of up to 4 to 16 inches long, 9 inches wide, and 4 inches thick, and can produce fruit in 3 to 4 years or less (3).
Spineless cacti make striking potted plants like O. macrorhiza. They may require stakes for support, especially for the big established ones because of the shallow and narrow pot space.
In the landscape, they are popularly used as hedges and with a height of 10 to 20 feet, they make excellent barriers. Popular big Opuntia cacti are O. cacanapa ‘Ellisiana’ and O. ficus-indica.
Like an Aloe vera plant, this cactus can be used as first aid. The sap from the pads can soothe wounds and the extract from young pads is used as a laxative and a medication for diabetes.
In Mexico, the Spineless cactus is an important commodity contributing to their dairy industry. When fed to cows, the stems provide a unique and desirable flavor to processed dairy products. During the drought season, the cactus can also provide moisture and food to livestock and poultry.
(1) Savio, Y. Prickly Pear Cactus Production. University of California. 1989, http://sfp.ucdavis.edu/pubs/brochures/Pricklypear/. Accessed 21 March 2021.
(2) Smith, J. Luther Burbank’s Spineless Cactus. California History. 2010. https://online.ucpress.edu/ch/article-abstract/87/4/26/27366/LUTHER-BURBANK-S-SPINELESS-CACTUS. Accessed 21 March 2021.
(3) Thakuria, A. et al. Edible spineless cactus. Indian Journal of Dairy Science 73(3). 2020. P. 185-191.
*image by AlexShadyuk/depositphotos