Opuntia Blog

Opuntia turbinata, erect flowering stem, photo by Daniel Green

Colonies of Opuntia turbinata can be found in northeast Florida, especially in coastal northeast Nassau County. The species can also be found Duval County, FL and in coastal southeastern Georgia.

Opuntia turbinata produces two types of growth: 1) horizontal-growing, and soil-hughing cladodes create a diffuse pattern, and 2) erect stems that eventually arise from the horizonatal stems.

Over time the cladodes of the horizontal stems thicken and lignify extensively, and may even become deeply buried in beach sand. The erect stems are composed of smaller cladodes and seldom reach a meter in height; typically such stems are 50 cm or less. Essentially all of the flowering occurs on the erect stems.

There is little information on the Internet about O. turbinata, but you can read more about it here. I don’t know where it can be purchased. It is not expected to be particularly cold-hardy.

Austrocylindropuntia subulata, long leaves showing, click on photo for original large image at Flickr

Austrocylindropuntia subulata gows at high elevations in Peru and Ecuador, from 9,000 to 12,500 ft. Probably for this reason the plant has proven relatively cold hardy for me. It easily survived 16 F, and I think it would have taken 10 F in stride. Additionally, A. subulata was a stellar performer in Texas, even when it got year round rain.

A. subulata is reported to be a large plant in the wild, tree like. I never had a plant reach tree-like proportions, but I kept it in a relatively small 8″ pot and had to prune it back once year.

The interesting thing about A. subulata is that it holds its leaves a long time, and the leaves are large for an opuntiad. The leaves will drop if the plant is stressed for water. However; on winter I left the plant sitting in a sunny location that was sheltered from the rain, and the leaves on the top half of the plant stayed all winter.

The flowers are red orange, but my plant never flowered. Maybe I should have planted it in the ground and let it get tall.

You can read more about A. subulata here, and here.

It is not hard to find Opuntia phaecantha in the American Southwest; the problem is that there are things that look like it that will confuse you. However, the good news is that almost any imposter is as hardy as O. phaecantha. Additionally, if planted with good drainage, O. phaeacantha and the similar plants will tolerate a fair bit of spring and summer rain.

O. phaecantha flowers are typically yellow, but they may have yellow centers. The imposters might be O. tortispina, O. dulcis, or perhaps O. gilvescens. Just plant them where they’ll get lots of sun and “stand back.”

Opuntia phaecantha, New Mexico

Opuntia pusilla, garden plant

Opuntia pusilla (some refer to it as O. drummondii) is found along the Atlantic Coast of the USA and the Gulf Coast panhandle of Florida. It has been reported from Texas but I’ve never seen it there (but there is a lot of coast to search).

In the sand dunes O. pusilla has a hard look, a desert look. In the garden, in rich soil and with frequent water, it grows like a weed and becomes rich green and luxuriant. A single cladode grows quickly to crowd over the sides of an 8-inch-diamater pot in a year or two. The cladodes easily break apart and soon different pots are growing their own O. pusilla. I wonder if O. pusilla is an invasive species in some habitats.

The spines are amazingly vicious, perhaps expected from a big cactus but not so from the “look” of O. pusilla. Perhaps part of their nastiness is that the plant grows a nice safe-looking spinach-green. Also, the spines seem straight and without guile, but actually they have a wonderful assortment of barbs that prevent dislodging.

The flowers of O. pusilla are small for an Opuntia, but they are cheerful enough. They are a nice canary yellow; I’ve never seen any with a hint of red or pink.

I don’t know the extent of O. pusilla cold hardiness, but they can be expected to take zero F easily, even with snow and rain. The plant also enjoys water, growing fast in the summer if it has lots of water.

Opuntia pusilla, click image for original Web site (southeasternplants.com)

Opuntia bentonii with fruit

I’ve only seen Opuntia bentonii in Texas, and only in Texas within 40-50 miles of Houston. I’ve only seen O. bentonii growing along the coast, typically right on sand within sound of ocean waves.  In some ways O. bentonii looks like a short O. lindheimeri plant, with the yellow spines and the shape of the pads.

However, O. bentonii grows with O. lindheimeri on parts of Bolivar Peninsula (near Houston). O. lindheimeri is typically twice the height of O. bentonii, and O. lindheimeri grows back from the water, whereas O. bentonii tends to grow right up on the last dune before the waves. Additionally, O. bentonii has yellow stigmas whereas O. lindheimeri had green stigmas. Finally, O. bentonii has nearly spherical fruit, unlike the more elongate fruit of O. lindheimeri. 

O. bentonii was described in 1911, and then promptly forgotten. I think that everyone assumed any cactus with yellow spines was O. lindheimeri, which some seem to think is nothing more than a variety of O. engelmannii. But, O. bentonii is different from anything O. lindheimeri or O. engelmannii.

In cultivation the two plants are clearly different and easy to tell apart because O. bentonii has a “cleaner” look, a less rugged-spiny look. In the wild there are three main differences:

1. O. bentonii grows close to the water
2. O. bentonii is shorter
3. O. bentonii has semi-spherical fruit
4. O. bentonii has yellow stigmas

Growing along the ocean where there is little freezing cold weather, I’d be surprised if O. bentonii tolerated temperatures lower than 5 F or 10 F. But, it sure does tolerate salt water and lots of garden water.

Opuntia bentonii flower and buds

Opuntia leptocaulis, photo by Gary Nored

Opuntia leptocaulis (Cylindropuntia leptocaulis) can be found from central Arizona, to southern Oklahoma, east almost to Houston, and south into Mexico. It is sometimes called the pencil cactus because its slim stems are thought to resemble pencils. Actually, the name “leptocaulis” means “butterfly stem,” referring to the thin abdomen of butterflies.

Sometimes long-spined and short-spined O. leptocaulis plants can be found growing side-by-side, as well as plants with silver or gold spines. Some plants have ripe red fruit in December, and the plant has been called the Christmas berry cactus. O. leptocaulis can form single short plants, or plants to nearly 5-foot-tall, or they can form thickets. They are easy going plants that tolerate too much water, and way too much cold (zone 5b?)–though much depends upon where the plant came from (Brownsville, TX, or southern OK).

Opuntia leptocaulis, east Texas

Some of the rarest plants in the world are opuntiads. One paper from about 10 years ago reported one of the stumbling blocks that Opuntia spinosissima (= Consolea spinosissima)  faces.

“Opuntia spinosissima (Martyn) Mill. (Cactaceae) is an extremely rare taxon with a single remaining wild population of 13 plants located on Little Torch Key, Florida. The plants rarely set viable seeds…I hypothesize that O. spinosissima is a sterile polyploid and that the 13 extant plants are asexually derived from a single lineage.”

This is terrible news. Essentially, after reporting her studies and findings (abstract), the author (Dr. Negron-Ortiz) concluded that all of the plants at the remaining location (in the wild) are really the same plant (ie, they are all derived from rooted bits). The author concluded that all of the plants are self-incompatible (they don’t accept each other’s pollen); if any seeds are produced they are identical to the parent plant, and thus, identical to all of the plants. Lack of genetic diversity is a real problem that seems to cause sterility in this case.

Opuntia spinosissima, photo from www.plantsystematics.org

Nopalea cochellinifera flower

Nopalea cochenillifera is one of several Nopalea species. The plants have tubular flowers in red, pink, or orange shades (bird colors!). The tubular shape is produced not by a fusion of flower parts (as in a snapdragon) but by orderly and overlapping tepals (petals) that surround the stamens.

The Flora of North America online reports that the flowers are used by humming birds. If you examine the image above you can just imagine a humming bird hovering next to the plant, inserting its long beak, and retrieving copious nectar. I’ve had the pleasure of tasting the sweet nectar from N. cochenillifera–it is watery but sweet. Hummingbirds visit plants in full bloom in Houston gardens for hours on end.

The stems and flowers of Noplaea are edible and the plant is cultivated by humans. In addition to being edible, the plants are host to the chochineal insect, and are thus cultivated to provide cochineal dye.

Nopalea dejecta, image from Wikemedia

Opuntia lindheimeri flower, near Del Rio, TX

Some folks lump Opuntia lindheimeri into O. engelmanii, as a subspecies or variety. I prefer to think of O. lindheimeri as a different species that occurs in different habitats. In Texas, you’ll generally find O. lindheimeri east of the Pecos River (dry to wet), and O. engelmannii west of the Pecos river (dry to very dry). O. lindheimeri seems to occur all the way south to the Rio Grande River at McAllen, TX and east to the coast of Louisiana. Of course, the species continues into Mexico. In addition to wetness, O. lindheimeri will tolerate a fair bit of cold; I’ve seen plants growing wild in southern Oklahoma.

For a guide on how to differentiate the two species check out the O. lindheimeri page.  One tip that usually works concerns spine color. “O. lindheimeri spines are typically yellow, or range to shades of orange-yellow or may have reddish hues. O. engelmannii spines range from white, to tan, to brownish tints. O. engelmannii spines may (not often) be yellow, but are not rich canary yellow or shiny yellow.”

Opuntia lindheimier, near Victoria, TX

Opuntia dillenii, photo by Danny Green

 Opuntia dilleniiis a distinctive and happy member of the Opuntia genus. The specimens I grew in the Houston area were free of insect problems and disease, and seemed impervious to rain, humidity, and occassional frosty weather.

The Proceedings of the Professional Association for Cactus Development (formerly the Journal of the Professional Association for Cactus Development) put out a very nice article in 2008 (Böhm H, volume 10, pages 148-170, Opuntia dillenii, an Interesting and Promising Cactaceae Taxon).

It was nice to see the discussion of the name for this taxon as well as a recognition that, perhaps, the Flora of North America (online) might be able to be rivised in the future (regarding Opuntia taxonomy). 

Opuntia 'Ellisiana', Rising Star, TX

Opuntia cacanapa cv ‘Ellisiana’ is a spinless form of O. cacanapa. The wonder is that the plant is essentially without glochids as well as spines. You can readily handle the pads without (or mostly without) encountering any irritation. I guess it must taste terrible because the plant seems unknown as grazing material.

I’ve tried to locate Opuntia cacanapa or O. ‘Ellisiana’ growing wild, but have never been successful. I doubt that either is native to the USA. I don’t know the origin of the species but suppose it is northern Mexico.

I’d guess that O. ‘Ellisiana’ could easily take 5 F, and perhaps colder temperatures. I base this guess on the fact I saw large plants in Seymour, TX, an area that occassionally reaches 10 F or colder. O. cacanapa (the spiny version) also surives nicely at the Rio Grande Botanic Garden in Albuquerque, NM.

Opuntia 'Ellisiana', close-up view of cladode

Opuntia macrorhiza is, in some ways, similar to O. humifusa. The pads are often in the same size range and both plants wrinkle and flatten for winter. Overall, O. macrorhiza gives the impression of being a larger plant than O. humifusa, and its flowers often have red in the centers, whereas O. humifusa flowers are typically all yellow.

Opuntia macrorhiza, Travis County, TX, photo by Ed Utley

I have found O. macrorhiza along the Gulf Coast of Texas, inland from the water a few dozen miles (Houston, Corpus Christi), and I’ve found it in the scorching hot desert of New Mexico as well as the grasslands of Oklahoma. No doubt it extends well into Kansas, and perhaps Missouri and maybe more northly places.

When I have grown the plant it was sturdy, tough, and hard to overwater. Most forms bloomed bountifully. Some forms lack many spines, but of course they have numerous glochids.

The plant can look sad and woeful in mid- or late summer if it is not watered plentifully, but lots of water keeps the pads upright and the whole plant looking good.  Of course, it is an Opuntia, so it can go a Summer without water and seem no worse for the wear the next Spring. No matter what you do the plant will shrivel and wilt for winter.

Opuntia macrorhiza, New Mexico

There is a lot of good information on the Web about various hobbies. One topic that many cactus growers are interested in is grafting–this is a great method for those of us who live in no-so-idea for cactus climates. 

Opuntia humifusa graft

One page I’ve enjoyed reading is called Grafting on Opuntia compressa; it is provided by the Cactus Art Nursery. They offer a great series of photos showing how to use Opuntia compressa (= O. humifusa) as a root stock. It is an informative, well done page. Opuntia compressa is an excellent rootstock because it tolerates cold and wetness with ease.

The Cactus and Succulent Society of Israel also has a Web page on grafting.

Another source for information is from the Journal of the Professional Association of Cactus Development. The article is clear and easy to read; it is called “Cactus Grafting Methods.”

Opuntia humifusa, copyright Martha Younkin, 2009

When I think of Opuntia humifusa, I think of yellow flowers. However, there are plants with bits of red at the bases of the inner petals (tepals). This plant was photographed by Martha Younkin.

O. humifusa is found in multiple midwestern and northeastern states, and in southern Canada. It is impervious to wetness and cold. It is the ultimate cold-hardy and wet-tolerant cactus.

Texas has many Opuntia species, all of which are spectacular when in full flower on mature plants. However, O. atrispina is especially attractive because it produces light-yellow flowers that darken to salmon. A field of these plants in bloom is a special sight.

Notice the cushion shape of the plant in the photo; such a shape (covered with flowers) can hide a snake or two. The lesson I learned is to approach such plants slowly and with a stick. Usually there are no snakes, and if there is a snake it is usually not poisonous. However, it is the exceptions that make life interesting.

Although it is from a desert region, O. atrispina grows well in the Houston, TX area. It tolerates a lot of rain. The problem is that it looses its “tough, spiny” look.

Opuntia atrispina, near Del Rio, TX

An email contact wrote to me that Opuntia humifusa can be found at various places on the Atlantic Coast of Delaware; it sounds like I need to make a road trip. The only problem is that it is mid-November and decidedly cool. I don’t think there are too many good day-trip days left in 2009.

Maybe I’ll be able to report next week that I found Opuntia in Delaware!

Opuntia humifusa flower, unusual with a bit of red in the center, photo by Dave Ferguson

Not every succulent is a cactus; and some noncactus succulents are superb garden plants. One of these great plants is Sempervivum (hen and chicks). I was unable to grow these plants along the Gulf Coast of Texas because they always failed in summer, the victim of one sort of fungal infection or another. However, they are great plants for the mid-Atlantic states.

Sempervivum 'Centennial', image from Wikipedia

 There must be hundreds of different cultivars or Sempervivum, perhaps thousands; it seems like no one really knows because new plants are being introduced all the time. One nursery that sells many types is Squaw Mountain Gardens, in Oregon.

 One of the best things about Sempervivum is that the plants can have fantastic winter colors: multiple greens, pinks, various reds, green-blues, blues, purples, near-blacks, and grays. Then, of course, they can mix the colors and a single cultivar might have shades of pink, red, and blue in winter. Unfortunately, I haven’t found any that keep their best color in the warmer months.

 Sempervivums have fantastic shapes, a spiral of leaves surrounding a central growing point. The various rosettes are surrounded by other rosettes that are larger, or smaller, depending upon relative age. Often, when a rosette blooms (they are not known for spectacular flowers), it will die, but the empty area is often quickly filled in by ever expanding neighbor rosettes.  Aracnoidium types (spider web types) have a filament of gray fuzz over the leaves, giving them a nice look. 

Sempervivum arachnoideum, image from Wikipedia

Opuntia stricta pops up in many places along the Eastern Gulf Coast of the USA. It is

Opuntia stricta, Florida

generally thought to be native to Florida and adjacent states, but garden plants have been spotted in central Mississippi, in Houston, TX and even Dallas, TX.

The plants are not known as particularly cold-hardy, but they sure do tolerate wetness and endless rain. Hobby plants have thrived in compost (not rocky soil) in the Houston area, even in 2004 when rainfall reached 70 inches. As long as it was warm the plants just kept growing, and in the cold months they just shrugged off the wetness. 

In drier years, O. stricta grew in hot weather if it was watered. Without water the plant just glistened in the sun–ever the happy camper, but it did wilt if not watered enough. North of Houston the plant survived 17 F without any fuss; perhaps it will survive to 10 F, especially if germplasm is from northern areas. Overall, the plant is easy to grow, but it’s cold hardiness is unclear.

Opuntia stricta, garden plant, north of Houston, TX

Opuntia fragilis grows in the mid-West (see map by Eric Ribbens), the West, and into Canada. The plants are small and often difficult to find where they grow in grasses.

Multiple garden plants and rock garden plants are derived from O. fragilis, either as natural variants or as intentionally created hybrids. The flower colors range from white, to yellow (click to see photo from Tim Wilder), to pink (and dark pink).

Eric Ribbens (Department of Biological Sciences, Western Illinois University) has created several Web presences wherein he describes the biology of O. fragilis including: O. fragilis (opuntiads.com), O. fragilis (sciencecases.org), and O. fragilis in Illinois. Eric Ribbens reports that “O. fragilis hybridizes fairly easily, and wild hybrids are known with O. macrorhiza, O. polyacantha, and probably O. phaeacantha.”

O. fragilis is an outstanding plant for cold gardens because of its interesting mat-like growth, its beautiful flowers, and because of its tolerance for wetness.

Spiny Opuntia fragilis in winter, Cuba, NM

Opuntia basilaris is the archetypal “beaver-tail” opuntia. It’s pads are spineless and sometimes nearly elliptical (or triangular), suggesting the flat tail of a beaver.

Opuntia basilaris

O. basilaris is commonly found in the Mojave Desert, especially between 2,000 and 4,000 feet in elevation. However, I have observed plants growing over 5,000 feet in elevation near Las Vegas, NV on Mountains to the west (Mt. Potosi, Mt. Charleston), and near Beatty, NV. Such locations are nominally USDA climate zone 8 (or thereabouts). However, at 5,000 feet elevation, the plants must surely experience occasional very cold temperatures, perhaps as low as -10 F or colder.

Opuntia basilaris

Some Opuntia (and opuntiads) tolerate year-round rain as long as they have reasonable drainage. These may, or may not be cold hardy. In general, the plants on the list (below) grow from central Texas to Florida, and experience long rainy spells from time to time in their natural habitats.

Opuntia alta, south Texas (near Zapata), moisture tolerant, photo by Mike Burnett

For instance, Nopalea cochenillifera is easily grown in many gardens that don’t experience frost; it doesnpt matter if they grow in Florida (with year-round rains) or in California (with winter rains).  

These plants can tolerate year-round moisture, as defined by Houston, TX rains. They may, or may not, be cold hardy.

The photo is provided by Mike Burnett, a talented plant photographer and naturalist.

Preliminary List of Moisture-tolerant Opuntiads

1. Nopalea spp.
2. Ophuntia humifusa
3. Opuntia alta
4. Opuntia ammophila
5. Opuntia anahuacensis
6. Opuntia bentonii
7. Opuntia cacanapa
8. Opuntia davisii
9. Opuntia dillenii
10. Opuntia fragilis
11. Opuntia gilvescens
12. Opuntia imbricata
13. Opuntia kleiniae
14. Opuntia leptocarpa
15. Opuntia leptocaulis
16. Opuntia lindheimeri
17. Opuntia macrorhiza
18. Opuntia nitens
19. Opuntia orbiculata
20. Opuntia polyacantha
21. Opuntia pusilla
22. Opuntia pyrocarpa
23. Opuntia sanguinicola
24. Opuntia stricta
25. Opuntia turbinata

Opuntia orbiculata is very cold-hardy, growing into north Texas and southern Oklahoma

I looked through the list of Opuntia species that I have grown, or that I have encountered, and I think there are over four dozen that can be classified as at least “moderately cold hardy.” For me, moderately cold hardy means that the plants will likely survive 10 F, if properly acclimated to the cold and not too wet.

 Wetness is typically a factor in cold hardiness; plants that are too wet in the winter and spring can rot, even if they are able to tolerate the cold under optimum (dry) conditions.  Thus, I can think of three different lists to put together: 1) cold-hardy plants, 2) moisture-tolerant plants, and 3) cold-hardy and moisture-tolerant plants. Of course, there is a fourth list that is possible: plants that are cold-hardy to -10 F. (Note: 10 F corresponds to -12 C;  -10 F corresponds to -23 C).

The list below contains those plants that I think are intrinsically cold hardy when they experience typical (ie, natural) growing conditions. The list doesn’t contain plants I think might be “iffy” or Cylindropuntia spp. This list contains many species that will be cold hardy to 0 F, -10 F, or even colder.  For another list try Benny’s Kaktus list. 

 Preliminary List of Cold-hardy Opuntias

1. Opuntia angustata
2. Opuntia arenaria
3. Opuntia atrispina
4. Opuntia aurea
5. Opuntia aureispina     
6. Opuntia azurea           
7. Opuntia basilaris
8. Opuntia cacanapa       
9. Opuntia camanchica
10. Opuntia charlestonensis
11. Opuntia chisosensis    
12. Opuntia chlorotica
13. Opuntia confusa 
14. Opuntia curovspina 
15. Opuntia cymochila
16. Opuntia cyclodes
17. Opuntia debreczyi
18. Opuntia dillei             
19. Opuntia dulcis
20. Opuntia engelmannii
21. Opuntia erinacea        
22. Opuntia flavispina      
23. Opuntia fragilis
24. Opuntia gilvescens
25. Opuntia gregoriana
26. Opuntia humifusa
27. Opuntia leptocarpa
28. Opuntia lindheimeri
29. Opuntia mackensenii
30. Opuntia macrocentra
31. Opuntia macrorhiza
32. Opuntia martiniana
33. Opuntia microcarpa    
34. Opuntia nicholii 
35. Opuntia orbiculata
36. Opuntia phaeacantha    
37. Opuntia polyacantha  
38. Opuntia polyacantha  
39. Opuntia polyacantha
40. Opuntia pottsii
41. Opuntia pyrocarpa
42. Opuntia robusta
43. Opuntia sanguinicola
44. Opuntia santa-rita
45. Opuntia spinosibacca
46. Opuntia strigil
47. Opuntia tortispina
48. Opuntia trichophora 
49. Opuntia valida 
50. Opuntia woodsii
51. Opuntia wootonii
52. Opuntia zuniensis

I’ve been wondering about Opuntia spp. and environmental extremes. From my experience the two major problems have been moisture and cold temperature. Of the two, moisture has been a year-round problem, whereas cold temperature has been a problem for 2-5 months per year.

Interestingly, some Opuntia are wonderfully tolerant of moisture. In my experience these have either come from wet climates (eg, the eastern USA), or they have come from the seashore, or both.

Opuntia anahuacensis is a little-grown plant that occurs along the Gulf of Mexico in Texas.  I have seen the plant enduring puddles of sea water or puddles of rain water, growing almost in the sea or inland along a river.  No doubt moisture tolerant cacti are called upon by their environments to endure drought and heat, but some swampy places also insist that their inhabitants endure occasional flooding.  Opuntia anahuacensis seems to have adapted well to alternating drought and flooding. 

Opuntia anahuacensis, growing on Galveston Island, TX, near the waves; typical cladodes of O. anahuacensis have the shape of a ping pong paddle

I’ve grown a lot of Opuntia but not under ideal conditions. Some years ago I lived in Pennsylvania and grew O. polyacantha, O. fragilis, O. humifusa, and a few opuntiads that I could not identify at the time.

More recently, I grew Opuntia in east Texas where the winters can be cool but are seldom cold. Generally, the temperatures did not drop below 20 Fahrenheit in east Texas, unlike the situation in Pennsylvania where subzero temperatures were expected every year. Zero Fahrenheit is about -18 Celsius.

Growing Opuntia in Texas taught me that, even though plants were tolerant of the temperatures, I could loose them to fungal infections quite easily. There were a few things I tried to help limit fungal infections. I used fast-draining soil. I planted in shallow pots or included pumice in the soil to provide aeration. I used systemic fungicides, applied in Spring, midsummer, and late summer.  And I used a systemic insecticide, applied at least twice a year; plants that were free of mealy bugs and scale seemed to resist fungi better. 

Some plants never thrived, or even survived. These were often Mojave Desert plants, plants from localities with extremely low rainfall. Opuntia basilaris from southern Nevada never lived long, nor did O. ramosissima.

Grusonia pulchells (Opuntia pulchella, Micropuntia pulchells); this species grows in some of the driest terrain in Nevada