Tips from a Master Grower Author(s): Elton Roberts Source: Cactus and Succulent Journal, 82(1):32-40. 2010. Published By: Cactus and Succulent Society of America DOI: http://dx.doi.org/10.2985/015.082.0109 URL: http://www.bioone.org/doi/full/10.2985/015.082.0109

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BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. CACTUS TIPS from a master grower ELTON ROBERTS 9Xii\c  ZXZk`

lmost any large, globular cac- ing, as the buds themselves are also covered in tus can be called a barrel cac- wool. The seed pods of are also cov- tus. Then again, some peo- ered in wool, while the seed pods of ple call even small globular are naked. In all, the woolliness of the flowering cacti barrels. I’ve heard peo- and fruiting parts of Echinocactus set its ple in Colorado call a 10 cm- apart. Backeberg claimed echinocacti also never tall sclerocactus a barrel, and have hooked spines, like so many cacti do. But I even the larger echinocereus disagree. Both E. palmeri and E. polycephalus have are called barrels by some growers. But to most hooked spines, at least by my definition. growersA the true barrel cacti are members of I have had a lot of people ask why their gold- Ferocactus and Echinocactus. There are only a few en barrel has not bloomed, even though it’s 8–10w small-growing members of these two genera, but in diameter. Well, have to reach maturity, we call them all barrels for convenience. That a and for some cacti this can take a while. I have few grow rather columnar with age doesn’t real- seen golden barrels that were 20 years old and ly matter, either. In a pot most will remain man- bigger than a basketball and others the same ageable for decades. age not much larger than softball. Barrels can The differences between Ferocactus and Echi- be stunted by the container they are grown in, nocactus are not entirely obvious to most growers, and you can be sure a barrel won’t reach matu- and yet you can usually tell a Ferocactus when you rity if kept in a 4w pot its whole life. Plants that see one. Their thick, ridged spines in bright star- are never fed won’t grow much either. I’ve had burst clusters are one giveaway. And the juveniles customers report that their golden barrels hardly have such colorful spines that they can be found grew and never bloomed until they started acidi- for sale in hardware stores. One thing that sets fying their water. But once a golden barrel starts Echinocactus apart is that most form a woolly top to grow that dense woolly top, whether it takes when they are old enough to bloom. I’ve heard five years or twenty, it is old and large enough some growers call this woolly crown a cephali- to bloom. If you want to see an echinocactus in um, but this is not technically correct, since the bloom sooner, try E. parryi or E. horizonthalo- flowering part of the doesn’t have more nius, which will flower at baseball size. and more-closely spaced ribs and bristles like Echinocactus and Ferocactus plants come from a true cephalium. In contrast, the areoles on a hot, arid desert areas. I have seen plants grow- ferocactus can have short wool, but when a fero- ing on top of just a pile of rocks and doing fine, cactus throws buds, you can see them; they are so I provide them with a soil that’s a bit more not hidden in or covered by dense wool. Echi- open and fast-draining than my regular mix. nocactus buds are hidden in wool until they are And because in habitat the plant roots spread large enough to emerge from the woolly top of like spokes on a bike wheel, I try to give mine the plant, and even then they keep you guess- wide, shallow pots.

32 CACTUS AND SUCCULENT JOURNAL Echinocactus grusonii I think most of us know what the Golden Barrel is, but not every one knows the Latin name, Echinocactus grusonii. There are several variants in cultivation: the normal yellow-spined version (upper left), one with unusually short spines (lower right), one with gorgeous white spines, and a popular crested form. Quick from seed if given space to grow, old plants can reach two meters tall and almost a meter thick. It’s said the flowers can be 5 cm wide, but for me they are consistently smaller

(3.5 cm), and unless viewed from above, they’re pretty inconspicuous, especially when hidden by a ring of dry flower remains. Smell them with care; the petals end in quite a sharp point! Flowering areoles produce a creamy wool, and the sharp dead flowers persist while the wool slowly washes away. The species appears to be self fertile. Fruits are always filled with viable seeds even when not intentionally pollinated. I’ve had plants scar at 20° F when the cold hit right after heavy rains, but I’ve also had plants take 9° F without damage when bone dry. Black spot is a common malady on in-ground plants that get wet and cold at the same time, so protect outdoor plants with a rug on nights when frost is predicted.

Echinocactus palmeri It will take years to get Echinocactus palmeri to flowering size. My plants are 30-some-odd years old now, but they’ve been blooming for just the last five, though often I overlook the flowers, blending in as they do with the yellowish color of the wool—or worse, remaining completely submerged within it. My plants are 36 cm in diameter and 30 cm tall. There was a grand old specimen at a place where I worked that was about 65 × 60 cm, and in habitat they get to about three meters tall and a meter across. The flowers tend to be 5 cm wide, though 8 cm has been recorded. Mine have taken temperatures down to 16° F without showing any bad effects to the cold, but keep them dry over the winter.

2010 VOLUME 82 NUMBER 1 33 Echinocactus parryi Echinocactus parryi is rare in collections and is probably becoming more so in habitat as locals cut the plant up to make cactus candy. (And yet if you are caught with so much as a few wild seeds you’ll see what the inside of a Mexican jail looks like.) When not blooming I think that it is the wonderful, heavy-duty spines that beckon people to reach out and touch. I’ve never seen seed for sale, so I keep seven plants set aside as seed stock. Four of my seedlings, produced from my recently deceased mother plant, are now about blooming size after six or seven years from sowing. They’re in five inch pots and are now about 7 cm in diameter, spines and all. Seedlings from about 12 years ago are now 14 cm in diameter and 10 cm tall,

and I think these will start flowering within a year. My one remaining is now 22 cm in diameter and 18 cm tall, still a ways to go to reach the 45 × 30 cm they can reach in habitat. The flowers are wonderful: their brilliant yellow petals have a carmine red at the base that extends up the dense cone of filaments. They can be 7 cm across if spines don’t block the way. So far my plants have only bloomed once a year, but I’m hoping they’ll start blooming more often like some of the other species in the genus. In my area, where the humidity is low, the plants have taken temperatures down to 9° F without any scarring, though I’d suggest keeping them above 20° F, just to be safe.

Ferocactus fordii subspecies borealis The plant that we have known for many years as Ferocactus fordii has been divided up a bit. For the form found in most collections you can add subspecies borealis to the label. Ferocactus fordii subspecies fordii is from farther south in Baja California, has longer (7 cm) central spines, and flowers less readily. The plants we have long known as F. fordii have central spines about 4 cm long—that’s borealis. F. borealis will bloom at about tennis ball size, so if you thought you’d never be able to grow a fero big enough to flower in a pot, this one is for you. And the flowers—a reddish-pink-violet—almost never stop. During the spring, summer, and fall, if the plants are not in bloom, they will at least have several buds standing by ready to open. As a rule of thumb I do not water these plants over the winter (as with most cacti), but in habitat they are in an area where they do get some winter rain, and winters can get chilly. Kept dry, my plants have endured temperatures to 9° F and shown no damage. Nevertheless, many books claim that any plant from Baja California should be kept at or above 50° F. I have Mammillaria pacifica plants that have lived through 9° weather with no damage at all, and they come from about as far south as you can go in Baja. The specific habitat, elevation, and weather of a plant’s home matters.

34 CACTUS AND SUCCULENT JOURNAL Echinocactus horizonthalonius For as long as I have known of Echinocactus horizonthalonius there has been a controversy over its variety nicholii. E. horizonthalonius ssp hori- zonthalonius grows to about 18 cm tall and to 15 cm in diameter—according to Benson: “spiny, grayish, domelike low mounds.” They’re found from cen- tral-southern New Mexico east into Texas and down into Mexico. Benson described subspecies nicholii as hav- ing dark gray cylindrical stems taller and darker than the type subspecies. Though The NCL does not mention ssp nicholii, which occurs several hundred miles west of the species in the cen- tral-southern part of Arizona and adja- cent Mexico, it’s said that Anderson had them in his back yard, and he upheld the subspecies, remarking that not only is it taller (E. horizonthalonius rarely reaches 30 cm), but it also clus- ters “as a result of true branching as well as seedling establishment at the base of the plant.” Among the 16 plants I grow, it seems I have some of both. My tallest plant is 28 cm tall and 20 cm in diam- eter, and I have to assume that it is variety nicholii. Another is offsetting. One is a seedling that I found at the base of the offsetting plant. Others have widely spaced areoles, and I believe are variety horizonthalonius. Others have areoles close together, such that the spines form an almost continuous line. Now add to these wonderful spines some fantastic and variable flowers (to 7 cm and appearing four or five times per season) and what a plant! The plants are quite frost hardy and can take tem- peratures to 10° F, but I always keep them dry over winter.

2010 VOLUME 82 NUMBER 1 35 Ferocactus emoryi subspecies covillei I tried for years to forget the name Ferocactus covillei once Nigel Taylor explained that the name F. emoryi came first. But now the red-flowered form of the normally yellow-flowered F. emoryi is deemed a good subspecies, and the name is in use again (albeit at a different rank). I guess that I had the right name on my plant after all! Subspecies covillei is said to occur to the north of the type subspecies. The NCL says it “replaces ssp emoryi in Sonora (Mexico) north of the Sierra Libre between Guaymas and Hermosillo.” Long ago I saw the plant around Ajo, Arizona.

The first flush of flowers each year emerges as a ring of 7 cm candystripe blooms, which may open all at once, but cer- tainly within a day or two of each other. After this the plant will throw one to three flowers at a time off and on for most of the season, and if the conditions are right, at some point it will throw another ring of flowers just like the first. I leave the yellow seed pods on the plant till they dry out.

Echinocactus polycephalus Echinocactus polycephalus grows in rocky desert areas in southern Nevada, southeastern California, western Arizona, and adjacent Mexico. It’s summers are blazing hot, and it sees cold winters, in some areas experiencing snow. The first ones I saw were just up from the floor of Death Valley, where you run across a beautiful population right by the road, where these cacti are the largest living things around. I have seen wild seedlings an inch in diameter and tremendous clumps over a meter wide with individual heads 25 cm in diameter and about 70 cm tall. Plants growing in rock cracks might be just 10 cm tall with 10 heads spanning just 30 cm. Flowering on this plant has been infrequent, and only this year have I seen the flowers myself. This is the first year it has wanted to bloom in about five or six years, to which I credit my new acidic watering regime. E. polycephalus produces a tan wool, though this does not signal imminent flowers. It’s the appearance of cotton-ball-like buds that indicates that the

plant is going to bloom. Interestingly, though, not every ball will throw a flower, so presumably some are aborted. Several weeks pass before buds emerge from these balls, and then the flowers open quickly: the same day or the next. The outer petals of the flower are pinkish-red and end in a spine. The plants are most conspicuous when the seed pods are ripe, since desert mice come around to eat the seed. To get to the seeds the mice have to chew off the covering of spines, and as they root around in the wool they make quite a mess, fluffing the cottony wool up to five times normal size. Perhaps that’s why some people call these plants “cotton tops.” Give these plants a fast draining soil. Even though in habitat they get some winter rain or snow, I keep my plants dry over the winter. They can take temperatures down to around 10° F. For best growth give them a hot and very bright spot in the hothouse, and allow the soil to dry completely between waterings. It will not hurt if the soil is dry for weeks at a time, but keep it damp a bit too long and the plant is a goner. If they loose their roots it can take a long time to get them to root down again—if you’re lucky!

36 CACTUS AND SUCCULENT JOURNAL Ferocactus horridus I have had this plant for many years under the name of Ferocactus horridus. Once Nigel Taylor decided it was just a form of F. peninsulae the name disappeared from cactus books. Now the very same plant has a totally new name: Ferocactus wislizeni ssp herrerae, or if you follow The NCL, Ferocactus herrerae. Species again, after all. But wait just a minute! F. horridus and F. herrerae come from just across the Gulf of California from each other, horridus from the east coast of Baja California, herrerae from the coastal area of the mainland. Surely someone will soon claim they’re the same. Don’t go changing your labels just yet!

The confusion mounts, since The NCL describes plants with spines that are not flat on top. Mine have both flat and rounded central spines. It also calls for plants to have straight centrals, and yet they show a photo with of a plant with curved to hooked spines. My plants have 7 cm yellow flowers with a red midstripe up the petal, as described in the book’s text. Yet their photo shows a flower without the midstripe. Useless. Whatever the plant is, it does well in my regular soil mix. I keep it dry over the winter and it has fared well down to 25° F.

Hamatocactus sinuatus subspecies papyracanthus These days Hamatocactus is considered to be part of Ferocactus. Its flowers are yellow or yellow with some red at the cen- ter, but the plants lack the heavy duty spines of Ferocactus. In fact, some have long, thin spines—nothing like what I think of as a ferocactus! The seed pods are different, and even the flowers to me just do not look like a ferocactus flower. From a horticultural perspective, hamatocacti are easy to grow and grow faster than other barrels. I grow Steven Brack’s collection SB 282 of Hamatocactus sinuatus papyracanthus. Descriptions say the plant can get to 30 cm tall and to 20 cm in diameter. I have had my plants only a couple years, so they are still small: 9 cm in diameter and 7 cm tall. The spines have quite a spread—long, twisting, and contorted to just over 10 cm long. The longest of the four paperlike centrals also has a hook. They are not rounded on the underside as described in some descriptions but flat top and bottom. The plants bloom at a young age—mine at just three years from seed—with flowers to 7 cm in diameter. Most Hamatocactus species start blooming in late spring and can bloom till it gets too cold for the buds to grow large enough to open. Most members can also take cold down to a few degrees below freezing if kept dry over the winter, but this species comes from Jaumave, in Tamaulipas, Mexico, so they may not like temperatures much below the freezing mark. I haven’t had them long enough to test them out.

2010 VOLUME 82 NUMBER 1 37 Ferocactus rectispinus Ferocactus rectispinus is the long spined ferocactus, but just how long can the spines be? Depends on who you ask, and the books have values all over the map. The New Cactus Lexicon says to 25 cm. I measured spines on a friend’s plants, and they were 27.5 cm long—that’s nearly a foot, and the longest spines I’ve seen on this species. While The NCL says that the spines are straight, all the plants I have seen have spines that have a bit of a curve to them. Plants in habitat can have both, as Britton and Rose show in their Cactaceae, though Taylor claims that the curve in the spines comes from hybridization with F. peninsulae.

Some sources have reduced the name to subspecies rank under Ferocactus emoryi (why, I can’t tell), though there’s little doubt that the name rectispinus will be lost—it’s too well known and so wonderfully descriptive. Young spherical plants with their luxuriantly long spines and 6.5 cm clear yellow flowers are great in a pot. The plants will eventually become columnar: to 2 m tall and 45 cm in diameter, but ferocacti tend to be restrained by their pot size, and therefore remain manageable for a long time.

Ferocactus robustus I photographed one of my Ferocactus robustus plants after cleaning it up, and then realized you might not believe me if I told you that by October 12, 2008 when the photo was taken, the plant had produced 82 flowers, and as you can see, it’s not done yet. So I’m also showing a plant with the dead flowers still on to prove it. Among the five plants I grow, there must have been between 300 and 400 flowers (each 7 cm across) in one 4–5-month period. I attribute such exuberant flowering to the acidic water I applied the entire season. F. robustus is interesting in that, rather than forming a single large barrel, it makes a large cluster of smaller heads, and in this way becomes the largest species in the genus. The largest plant known is over five meters across, with heads about one meter tall in the center of the mound. On my plants the largest head is 18 cm in diameter, spines and all, on a clump just 34 cm across. F. robustus comes from the Mexican state of Puebla, quite a ways south in Mexico. While my plants have experienced cold down to 16° F, this has resulted in dark spots forming on the body, and the cold causes the lower areas of the stems to get grungy. To keep the plants from disfiguring, try to keep them at or above about 40° F over the winter.

38 CACTUS AND SUCCULENT JOURNAL Ferocactus latispinus There are two well-known ferocacti that look a lot alike: Ferocactus latispinus and F. recurvus. Some authors maintain the names as separate, and some use latispi- nus as a subspecies, as in F. recurvus ssp latispinus. The recurvus form lives farther south than normal latispinus and exhibits differences in spine width and flower color. In F. latispinus the central is flat and about 9–10 mm wide. On F. recurvus it’s narrower at 6 or 7 mm. F. latispinus has a uniformly pinkish purple to magenta flower (or whit- ish yellow on some plants), while the flow- ers on F. recurvus are described as white with pink to purple midstripes, with a center (the base of the petals) much darker than in F. latispinus. Both bloom in the late fall to mid winter. It will take some years to grow a small plant to the size of the 40 cm

wide × 30 cm tall plants in habitat, and I’ve found that the plants have the tendency to get taller than wide in cultivation. I’m also showing a plant (below) I long had labelled F. recurvus spp greenwoodii. It turns out to be simply a yellow- spined variant of F. latispinus. Named by Charlie Glass, it is supposed to have just one central spine, rather then the four you see here, and a dark-pinkish-purple-centered flower like F. recurvus. As these species come from quite a large area of Mexico, and from different elevations, it is hard to know which plants come from areas where they can take some frost and which, like those from the southern reaches of its range, cannot. So it’s safest to keep the plants above about 40° F to avoid scarring like you see in the uppermost photo above. For good spine growth give as much bright light as possible.

2010 VOLUME 82 NUMBER 1 39 Echinocactus texensis Though originally described as Echinocactus texensis, in the early 1920s Britton and Rose dubbed this plant Homalocephala, so it was known until about 20 years ago. But everyone knows it as the famous Horse Crippler. It’s said its spines can penetrate a horse’s hooves, and in Texas the plants have been systematically eradicated, stacked top down along fence rows to die. Nevertheless, they remain common and are well known in southeastern New Mexico, Texas, and into adjacent Mexico. Anderson even claims that it can be found in parts of Oklahoma, though I haven’t heard that from any other source.

The description calls for a solitary stem to 30 cm across and to 15 cm tall—charmingly squat and pancake like. In cultivation they get somewhat larger. I have two plants nearing 40 cm, and one has a large offset as well! Watch out for the spines. They are very stiff and hard. And though such a rugged plant might be expected to have a rugged flower, instead we get blooms with lacy edges on icy pink petals and a blush of red in the center. If the flower is pollinated, a 4 cm hot-red berry forms with a color that lasts till the pod dries out. I’ve grown my plants outside for years in an open, fast-draining soil, and these plants can take the cold—to 10° F at least. The only problem with having them outside is controlling weeds. Those mean spines are ready to get you.

40 CACTUS AND SUCCULENT JOURNAL