CACTUS: SOURCE OF PERHAPS THE PERFECT FRUIT
SCIENTIFIC NAME: Many Genera and species
FAMILY: Cactaceae
Consider cacti. Few other plants can offer so much to gardeners who live in the arid climates so typical of California. Native Americans of the American Southwest and Mexico have for ages known and enjoyed the fruit of at least 14 species from this large and useful family. The Indians of California as well as those of the desert Southwest and Mexico have also used the flowers and stems of some cactus species as food.
The peoples who lived in the desert of the Southwest and California long before Europeans appeared have sustained themselves on the fruits and flesh of cactus since ancient times. Park S. Nobel, in his splendid book Remarkable Agaves and Cacti, cites archaeology that unearthed nine-thousand-year-old mummified human faeces in Mexico that contained fragments of agaves and cacti.
Cactus fruits were eaten fresh or dried, or fermented into wine. Cooked fruits were sometimes boiled, salted and mixed with corn flour. Fruits chosen for wine making are known to have included those of cardon, organ pipe, Pitaya agria and saguaro. Fruit-gardening home winemakers in California might wish to experiment for themselves.
The seeds were often removed and eaten separately. Sometimes this occurred after the original fruit had been digested and this practice was known as "the second harvest." Seeds of the prickly pear, or tuna, are still sometimes roasted and ground into meal.
Even the flower petals have been eaten with relish, especially those from the barrel cacti. In fact, again according to Nobel, a "cactus moon was celebrated in early spring when the flower buds of various species of Opuntia were cooked or roasted as a special treat."
The flesh of prickly-pear stems, correctly known as cladodes, were, and still are, eaten, sometimes after roasting. Nopales, cactus pads harvested from prickly-pear cactus (Opuntia ficus-indica), are an important crop in Mexico. They are also easily available in the United States, particularly in Southern California and throughout the Southwest. They are sold commercially to be braised and eaten as a vegetable, often cooked with onions, peppers, cheese, eggs, spices and even meat, to make fillings for tacos and other dishes.
How to Start
Those with Opuntia in their gardens, and who wish to experiment, should start with very tender young cladodes. Choose ones that are thin, dark green and no greater than 12 inches long. The areoles from which the spines and glochids grow are still prominently raised above the otherwise flat surface on a pad this young. (Glochids are basically those pesky minute barbed hairs growing out of the prickly-pear cactus pads and fruits, the things that get under your skin and annoy you for days, if you don't take precautions to avoid them. They can also, as I found out to my chagrin, trigger warts in susceptible people.)
Use a sharp knife, moved at a grazing angle to the cladode surface, to scrape off the unwanted bumps while retaining as much of the stem tissue itself as possible. Nobel mentions that a potato peeler can also be used to remove the areoles which, though slower and shows far less flair, requires less skill. Other species of cactus that have historically been eaten for their stems include teddy bear cholla (Opuntia bigelovii) and chain-fruit cholla (Opuntia fulgida).
Other traditional uses, according to Nobel, include the woody ribs, that the Indians fashioned into poles, as handles for tools, for constructing shelters and as torches. The roots and juices were used in the concoction of remedies for various ills. Juice from saguaro flowers was used as a sealant, and pitch from the stems of organ pipe and pitaya agria was used on boat seams and pottery. Containers were made from barrel cacti, cardon and saguaro. On a somewhat darker note, he cites the use of barrel cactus stems as tables for human sacrifices.
Ordinary gardeners, however, are more likely to be attracted to cactus for their sculptural forms, flamboyant flowers and, for those in the know, their delicious fruits. Beekeepers also prize cactus flowers for the splendid honey their nectars can produce.
In California, the only cactus fruit consistently available commercially is the tuna, Opuntia ficus-indica, aka prickly pear or Indian fig. The popularity of the prickly-pear cactus in California pretty much echoes sentiments in the entire western hemisphere. In fact, the cultivation of Opuntia ficus-indica is worldwide. According to The Complete Book of Fruits and Vegetables, by Francesco Bianchini, Francesco Corbetta and Marilena Pistoia, "The Indian fig (Opuntia ficus-indica of the cactus family) has been part of the European flora since around the sixteenth century. The Spanish imported it from Mexico to Europe soon after the discovery of America. It is therefore of American origin, and spread rapidly in the temperate and warm regions of Southern Europe and Africa .... [A]round the Mediterranean, the Indian fig has become very much part of the countryside, often making a magnificent display."
According to Popenoe in his classic Manual of Tropical and Subtropical Fruits, "among the aboriginal inhabitants of tropical America, the tuna has long been held in high esteem. Early introduced into Southern California by Franciscan monks, Opuntia is found abundantly, particularly around the old missions. Now Opuntia, particularly O. ficus-indica, is cultivated and naturalized throughout the tropics and subtropics."
The ripe fruit of tuna, writes Popenoe, contains 19.66% total solids, 0.40% ash, 0.18% acids, 0.98% protein and 2.79% fibre. Nobel cites cactus fruits as being high in sugars (approx. 70-80% by dry weight). About one-third of the sugar content is fructose, which is better tolerated by diabetics than glucose and sucrose. Cactus fruits are also high in vitamin C and low in fats, although the seeds, often eaten with the fruit itself in many species, prevent these fruits from being entirely fat-free. The percentage of carbohydrates, almost all assimilable, is around 10%, but this figure is possibly lower than the actual amount to be found in the ripe fruit soon after harvesting. The mineral salts are few, mostly of the same type as found in other fruits.
According to Bianchini, Corbetta and Pistoia, some of the more popular tuna cultivars, at least in Europe, include: "The yellowish Indian fig; the ficodindia surfarina of Sicily with very sweet firm pulp; the violet-red Indian or 'bloody' fig of small size; the late bastarduni Indian fig, large with sweet pulp and excellent for prolonged storage ... "
In Australia, because of the rampant and once disastrous growth of certain species, including O. ficus-indica, O. stricta, and O. vulgaris, fruits of the whole genus came to be called "pest pears." After their introduction in 1832, the plants naturalized. Plowing them under only created more of them, because sections could root and grow, and they began to take over new rangeland at the rate of 250 acres an hour! Many futile attempts were made to control and eradicate these plants. It was only after the importation of the moth Cactoblastis cactorum that the infestation was brought under control.
Tuna has small but very woody seeds. Although the seeds are innocuous when digested, they are somewhat annoying and can break a tooth of a careless person. Although the glochids are usually brushed off from commercially available tunas, home cactus gardeners learn soon enough to wear gloves when harvesting and to carefully brush away the annoying pricklers before touching them with bare hands.
When ready to eat, peel them by first cutting away a small amount of the top and bottom then making a slit end to end through the rind. Park S. Nobel describes many other creative treatments he has seen. In Mexico, for instance, the seeds are often removed by pressing the peeled fruit through a colander. This pulp is then boiled into a thick syrup that can be used as a syrup, or reduced further and sold as a taffy known as 'miel de tuna'. The pitted pulp can also be boiled for about 8 hours, reduced, cooled and formed into cakes called 'queso de tuna' (literally cactus-pear cheese) sold in a brown, brick-like form. Freshly peeled whole fruits can be hung on a string and, after drying for a couple of weeks, these pulps become coated with a sweet sticky juice that can preserve the dried fruit inside for many months.
Tunas, however, are not the only choice available to Americans, at least not to Californians who can grow alternatives in their mild climate. According to Popenoe, "The fruits of many cacti known in tropical America by the name pitaya [also phonetically spelled a variety of other ways] are commonly larger than tunas, and by some are considered superior to the latter in quality, but their use is less extensive. The widely cultivated plant which usually passes under the name of Cereus triangularis is properly Hylocereus undatus [which, according to Popenoe, in his time, at least, was found only in Jamaica]. All of these plants are climbing in habit, and have triangular stems. They produce large, showy, night-blooming flowers, and oblong or oval fruits, bright pink to red in colour, sometimes more than 3 inches in length with large leaf-like scales on the surface. These will grow outdoors in parts of southern California.
The fruit of Cereus peruviana, a white-fleshed fruit with a bright pink skin but lacking the leaf-like surface scales is also known as a pitaya. One reason for the lack of commercial success for these fruits may lie in their fragility. They do not have a long shelf-life. Unless refrigerated, their pulp soon deteriorates into an unpleasant mucus-like texture.
Good for California
A fine cactus fruit especially adapted to California is the fruit of the previously mentioned Cereus peruviana. These cacti have hexagonal stems, reaching at maturity a height of 15-20 feet. Their dramatic lily-shaped white blossoms open at night through early morning. From these flowers develop sweet, white-fleshed, perfumed fruits that come with an electric pink skin that must be removed. Their seeds, the size and hardness of chia seeds, are sprinkled through the pulp and can easily be eaten.
Spectacular specimens of these are found in the desert section at Huntington Gardens. Those who live farther into the desert also enjoy access to the fruits of barrel cacti (Ferocactus acanthodes, F. covillei and F. wislizenii) and organ pipe (Stenocereus thurberi). According to Nobel, other, perhaps less familiar, fruit-bearing cacti include chain-fruit cholla, desert Christmas cactus (O. leptocaulis), Englemann prickly pear (O. phaecantha), pencil cholla (O. arbuscula and O. versicolor), and purple prickly pear (O. violacea). Other cactus genera producing edible fruits include: fish-hook cactus (Mammillaria estebanensis and M. microcarpa), golden hedgehog cactus (Echinocereus engelmannii), and pitaya agria (Stenocereus gummosus).
Somewhat distinct are the pitayas from several species of Lemaireocereus, notably L. griseus and L. queretarensis. These are common wild plants in Mexico and elsewhere. L. griseus is often cultivated. The fruits are globose, about 2-1/2 inches in diameter and covered with many small clusters of spines. These are brushed off the red, fully ripe fruit, leaving it in condition to be eaten. The flesh is dark red to purple, sweet and delicious in flavour.
The propagation and culture of these plants resembles that of Opuntia. The Hylocereus group, however, is much better adapted to a moist tropical climate than the tunas. The most important genus of pitaya in Mexico is Stenocereus. After harvesting, these fruits are processed into equivalents of the various food products made from the prickly pears (tunas). A Stenocereus relative harvested from the wild, Escontria chiotilla, is especially valued for marmalade and ice cream. Less popular cactus fruits, such as strawberry cactus (Echinocereus stramineus) and various species of barrel cactus and Mammillaria are also harvested. Flower buds of barrel cacti are often fried with eggs or boiled with chilies In Colombia, increasing acreage is being planted to the delicate and delicious Hylocereus triangularis (aka H. megalanthus and H. undatus).
Cultivation
One reason for cactus's popularity lies in its ease of cultivation. Popenoe quotes J.W.
Tourney, writing in Bailey's Standard Encyclopedia of Horticulture, who points out: "It has been ascertained that some of the best varieties are capable of producing on lean, sandy or rocky soil ill-suited for growing ordinary crops, as much as 18,000 pounds of fruit to the acre. When it is considered that this is equal to 2,500 pounds of sugar, as well as other valuable food constituents, it may be seen that the food value from the standpoint of nutrition is considerable."
In other words, an excellent food crop for marginal land in a warm, dry climate.
Tourney describes commercial plantations as usually being planted on dry slopes of hills, because the plants do not thrive where there is much moisture or on heavy clay soils. The plants are propagated vegetatively, using joints, cut or broken from the plants. These are planted at distances of 6-8 feet in furrows from 615 feet apart. No tillage is practised as they grow rapidly, and in a few years smother out all other growth. Before planting, the cuttings are exposed in half sunlight from 7-15 days, that they may partially wither, in order to facilitate rooting. Tourney goes on to explain that "An important advantage in the culture of these plants is the regularity of the yearly crop. They begin to bear in about three years after planting and continue bearing for many years."
The roots grow at shallow depths in porous sandy soils because they have been adapted to respond to the light rainfalls that occur in arid regions and do not wet the soil very deeply. Wetting of the soil by rainfall induces the growth of new roots. In the wild, nitrogen is often the soil element most limiting for growth. Fertilization with nitrate-containing inorganic fertilizer or manure almost always enhances the growth of cultivated cacti. A field of Opuntia ficus-indica raised for nopalitos near Mexico City is fertilized annually with a 9-inch layer of cow manure. Nobel points out that whether applications of phosphorus and potassium increase the growth of cacti depends on the element levels already in the soil. Sufficient boron for growing cacti is present in the form of borate in the soils of the southwestern United States.
Most cacti do not tolerate soil salinity well. This means that gardeners or professional growers using drip irrigation must take care to prevent salts from accumulating in the root zone. Nobel suggests that since cacti graft easily, one solution is to use a rootstock that can tolerate salinity such as Opuntia quimilo, a species from Argentina. Cereus validus is another Argentine cactus adapted to regions that have salt flats during the dry season. Apparently, its feeder roots succumb to the salinity and drop off during drought. After next season's rain dilutes the sodium, new main roots grow, which in turn are shed during the next dry season. Much more work needs to be done to determine how successful such grafting can be, especially on a commercial level.
Sicilian Revenge
Nobel describes a really outstanding cultivation trick - removing the flowers in early summer to create larger, better fruit later on. Apparently, this technique was discovered in Sicily as the result of someone's desire for revenge. One popular legend has it that a Sicilian farmer, enraged by the advances of another farmer toward his daughter, knocked all the flowers off his neighbour's prickly-pear plants.
The other legends all basically follow the same theme, with variations in casting and setting.
Whatever the true origins of this technique, Sicilian farmers know that removing the first flowers causes the cactus to flower again. Although fewer blooms are produced during the second blossoming, these develop into larger, sweeter fruits that ripen in late autumn. This practice is called scozzolatura, which means "to take the buds away." Labourers go through out Sicilian fields of cultivated Opuntia ficus-indica with ladders and sticks, deliberately destroying the first fruit crop.
Again according to Nobel, in Sicily, in commercial "groves," each cactus is planted at intervals of 13-15 feet in rows that are 16-23 feet apart. Taking into account the practice of scozzolatura, about 8-10 fruits mature per terminal cladode. In return for that slight effort, a superior crop of fruit is produced.
Cacti, these plants that offer so much to fruit and ornamental gardeners alike, appear, at least in modem times, to be vastly under-utilized. As water resources become stretched to satisfy ever greater demands - for instance when other states and Mexico began demanding an ever-larger share of the Colorado River water, professional growers and gardeners alike, feeling the pinch of scarcity and higher prices, might start looking with renewed interest at this versatile family of plants.
Cactus: A Friend in a Fire
If I lived in one of the canyons or in any other fire prone area, I would plant cacti around my house ... lots and lots of big, fat, juicy cacti. Here's why.
A while back, early on a Saturday morning, I was awakened by a loud cracking noise. Imagine my surprise to see instead of the noisy, inconsiderate boob I suspected - my neighbour's garage fully engulfed in a huge fire. I called 911.
By the time the firefighters got there, not too much later, the fire had spread in all directions. After burning down the structure, it blackened my neighbour's yard to the south. It leaped over the back alley and started consuming another neighbour's cedar-stake back fence. It licked across the five foot span between my garage and his, caught mine, and burned it down, too. But... When the fire reached the venerable Cereus peruviana growing about 8 feet south of my neighbour's late garage, it singed and browned about half that tall, fleshy, water-filled plant, petered out and didn't travel further.
Another neighbour had planted an orange tree that reached over his cedar-board fence, shedding shade, and sometimes oranges, into the back alley. The first five feet of fencing burned so badly he had to replace it. The tree, blackened by the flames, never recovered and had to be removed.
A few feet north of the citrus, he had planted a banana. Under and around it, the fire had burned the fence black, and the banana brown. It eventually came back from its corm in the ground. The blistered and blackened stretch of fence had to be replaced.
More or less in the middle of his back fence, a huge Opuntia cascaded over and down, decorating our shared alley with its flowers and fruit. The edges of that cactus closest to the flames ended up browned, but the rest survived, apparently unscathed. More important, the wood directly below and to the north of that cactus remained untouched. The fire never got past the cactus.
Large cactus plants, I saw, can really make a difference. Which is why, if I lived in Malibu, I'd surround my house with a hedge of the largest cacti I could find.
DATE: July 1996
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