Fruiting Cactus

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Recently Fruit Gardener, the magazine of the California Rare Fruit Growers, has featured articles on Dragonfruit and Peruvian Apple Cactus. While these and the Indian Fig Cactus are certainly the most well known and most utilized fruiting cactus, the cactus family includes many more examples of cactus bearing edible fruits of local and regional significance. Arizona (and much of California) is an arid region, unsuitable for many of the commonly grown temperate and subtropical fruits. Population growth has strained water resources, raising the specter of future restrictions on water use. Future fruit gardeners in the Southwest may want to learn more about growing cactus as a way to adapt to these changing conditions. Gardeners in less arid regions may find cactus virtually maintenance free, productive and even good to eat! Because past articles have focused on the triad of fruiting cactus mentioned above, this article will be discussing only those other species of cactus utilized on a regular basis for their fruit. The Table Cacti as Food lists them along with information on hardiness. For reasons of limited frost tolerance, time to maturity and fruit production and even eventual size, not all of these plants are suitable for cultivation in our area. However, the essence of a rare fruit gardener is to push the limits and to try what the pundits would call the impossible.

Cactus fruit can generally be divided into those that are dry at maturity and those that are moist. In the latter group, all cactus fruit are technically edible, that is nontoxic, but not necessarily palatable. Further complicating their consumption are the numerous seeds embedded in the pulp, which makes many unsuitable for out of hand eating. The seeds are, however, a food resource themselves, being high in protein. Many traditional utilizers separate and process the seeds by roasting or grinding as an additional food item. This is possible even for cactus whose pulp is unpalatable otherwise. The term Pitaya or Pitahaya is a Spanish term, which is generically applied to all cacti with edible fruit and some without. The ubiquity of this use underlines the importance of knowing the scientific name as well as the common name for our plants.

As the table accompanying this article illustrates, there are too many varieties of cactus to do a detailed discussion of all of them. That would be more suitable for a book than an article in Fruit Gardener. I would like to discuss primarily some of the more important groups, skipping those that have already received attention as well as those that would be impractical to grow by reason of size and/or time to maturity. These are mostly slow growing columnar cacti from consistently warm regions that must obtain a large size in order to fruit. A classic example of this type of cactus is the Saguaro of the American Southwest, which must be about 75 years old before it even begins to branch and bloom.

Surprisingly, not all columnar cacti follow this pattern. Quite a few are rapid growing and will begin blooming at a moderate level of development. Good examples of this pattern are the Stenocerei of Mexico – alamosensis, fricii, griseus, gummosus, montanus, pruinosus, queretaroensis, stellatus and thurberi. The unrelated columnar cactus Escontria chiotilla could also be included in this group. These plants have for many years been grown on a small scale for their fruit in rural Mexico and sold in local markets but are now under development on a larger scale for commercial fruit production.

One of the aspects of the Stenocerei or Pitayos is that they naturally succeed each other in the times that the fruit reach maturity. This succession is reflected in their common names. Thus, S. griseus is Pitayo de Mayo (May), S. fricii Pitayo de Aguas (season of rains – probably late summer) and S. pruinosus Pitayo de Octubre (October). Other varieties fill in the gaps, providing a near continuous supply of fruit.

Most Stenocerei are not frost hardy but may be able to grow in areas like Southern California or Phoenix with occasional frost protection. With supplemental water and fertilizer, they grow quite rapidly and may reach blooming size in 5-7 years from cuttings. I once purchased a  3 inch Stenocereus griseus seedling in a supermarket in El Paso, planted it in the ground inside my greenhouse here in Tucson and had it grow to a branched plant 8 feet tall in about 5 years with no special attention. It has been moved twice since then and has not yet bloomed but similar plants in Phoenix apparently bloom regularly.

Another Mexican cactus significantly utilized for its fruit is Myrtillocactus geometrizans, known as Garambullo. Garambullo can be best described as a candelabra cactus, branching early and frequently to attain stems and begins flowering and fruiting at an early stage. The fruit are small, juicy and brown and are quite comparable to raisins. The flavor is pleasant and the seeds are so small as to be unobjectionable. Most large nurseries with a cactus section will carry M. geometrizans for sale. The related species Myrtillocactus cochal and eichlamii are similar in flower and fruit but less hardy than M. geometrizans.

The final group of cactus I would like to touch upon are the Opuntias or Prickly Pears other than O. ficus-indica, the Indian Fig. The genus Opuntia is the most widespread and common in the cactus family, extending from Canada to Tierra del Fuego. The list of fruiting species in the table Cacti as Food is only a partial one, the actual list probably including many more species. Very little information is available, for example, on fruit use in the South American species. In Mexico, one can find the fruits of many more species than O. ficus-indica. Some of these varieties have already undergone significant selection for superior fruit production and are cultivated on a major scale. O. amyclaea, O.hyptiacantha, O. joconostle and O. streptacantha are all significant regional crops. Tunas vary considerably in size, color and flavor. Use, however, tends to be similar. Because of the large hard seeds, most tunas are processed to pulp or juice for use as syrups or candies. Mexican consumers reportedly prefer white fleshed varieties whereas Americans prefer red fruit with red flesh. Current breeding efforts are directed at encouraging parthenocarpy or the production of infertile soft seeds which would be less of an impediment to fresh consumption. Many Opuntias are frost hardy, especially in the mild winters of the Southwest.

This has been a brief introduction to cactus as fruiting plants. Cacti have a lot to recommend them as fruit, particularly their minimal water needs. Additionally, most cacti are not subject to pests and diseases in our region. They can be ornamental as well as useful, cactus blossoms being among the most beautiful nature have to offer. It is my hope that this article will inspire more fruit gardeners to devote some of that precious space to growing cactus for fruit.

Cacti as Food

Note from Sheryl:  I asked Chris to comment on what we call here Cereus peruvianus:                               

Chris:  Cereus peruvianus is not a valid scientific name. The plants grown as Cereus peruvianus are either hildemannianus or repandus, usually hildemannianus. The name ‘peruvianus‘, nevertheless, is very commonly used. Fruit is variable in quality but if you get a good one, very good flavour I like them much better than pitayas”. I use as my reference these days The Cactus Family by Edward Anderson. His taxonomy is controversial among cactophiles but it is the most up-to-date and comprehensive treatment of the family in many years. Cereus hildemannianus has 4-5 ribs, repandus 9-10. The flowers on repandus have more pink in them. C. hildemannianus is by far more common.