Ariocarpus revisited

It’s been a few years now since I last wrote about my all-time favorite genus of Mexican cacti, the Ariocarpus.  Then last week when I visited my greenhouse, I noticed a most astonishing and memorable sight — so many of them, across species, were flowering.  As a rule, Ariocarpus are fall and early winter bloomers.  The first blooms are produced around late August and may continue on till December in some cases.  And then that’s it with the flowering, till the next year.  So you can imagine how utterly (and pleasantly) surprised I was to see not just one or two, but a whole array of these very rare treasures flowering profusely last week.  There are seven or eight species in the genus, depending on which expert opinion you follow.  With the exception of A. trigonus (the photo shown here was taken in December of last year), all the other photos depicted here today were taken just last week.  Imagine, A. agavoides, A. bravoanus, A. hintonii, A. kotschoubeyanus, A. fissuratus, A. fissuratus v. lloydii, various A. retusus and A. scapharostrus all in bloom at roughly the same time!  Truly mind-boggling and a weekend I will remember for the rest of my cactus-growing life.  I took this sudden burst of blooms as a sign that I should write about these dear friends once again.

I am still trying to figure out what may have caused this sudden burst of blooms in my Ariocarpus.  It might be due to the suddenly cooler temperatures experienced again in February after a somewhat warmer-than-usual January.  This may have confused the Ariocarpus into thinking fall had come a lot earlier this time around.  Images of the effects of global climate change also come rushing into one’s cranium.  But I must also say that my plants in general are really doing so much better in their new location in the Tagaytay area, and the Ariocarpus are no exception.  Healthy and happy plants are the ones that flower regularly.  Now that I think I have finally found the right mix of location, plus the right growing medium and watering schedule, these once very difficult plants to grow for me have been somewhat of a breeze nowadays.  I have been growing these plants for over 30 years now.  Prior to moving them to their current location, I was only able to flower A. fissuratus twice!  No luck with the rest of the genus, which was a real disappointment for someone as passionate about these plants as myself.  All that past frustration has changed dramatically for me. The key lever of change in my case?  Location, location, location.  My plants are now housed in an area with essentially unobstructed access to direct sunlight and a super-abundance of fresh clean air flowing and ventilating their home. 

Ariocarpus are arguably the most coveted and sought after genus of cactus in the entire world.  Their unusual appearance is the first thing that catches one’s eye.  In fact, these plants don’t even look like cactus plants at all.  They don’t have spines (though one form of A. retusus, named “pectinatus,” may have a few weak odd spines at the tips of their tubercles; I don’t have this plant yet so I can’t really confirm this at the moment), and their curious large, flat tubercles with an angular keel along the bottom look more like leaves.  Some have likened this appearance to the small succulent agaves. 

Others have described these plants as “living rocks.”  In their native habitat in Mexico and southern Texas, these plants are set very low to the ground, and look deceptively similar to the boulders or soil of their surroundings.   In the wild, most of these plants are so well camouflaged that even experts who are out looking for them have extreme difficulty finding them unless they are in flower.

And boy, how can you miss these plants when they are in flower?  Their flowers, which range from the yellow of A. Trigonus, to the whites and light pink of A. retusus and its variants, to the pinks and magenta of the rest of the genus, are a true sight to behold, especially if viewed in the context of the “living rock” that produced the bloom.

I wouldn’t recommend Ariocarpus to beginners.  If not given the right growing conditions, these plants can be especially difficult to grow.  I should know, as I’ve managed to kill my fair share of these very rare jewels (what a fool I am).  It is absolutely essential to grow these plants with as much direct sunlight and fresh air as possible.  I also grow these plants in pure mineral substrates without any organic material added in.  The trick is to find a good sandy garden loam to use as your base.  Then add the appropriate mix of well-washed river sand, crushed lava rock and/or pumice.  I now also grow all my cacti in our good ol’ porous red clay pots.  The combination of the growing mix and the pot will insure good drainage is achieved.  Nothing will kill an Ariocarpus quicker than constant “wet feet,” where the growing medium fails to dry out completely after a few days.  Ariocarpus have large taproots that, while storing water for the plant’s needs, are also very sensitive to rotting from sitting in constantly wet conditions.  I water my plants once a week during the entire year.  When I water, I make sure to give my plants a good soaking where the entire root ball receives water.  I find that Ariocarpus enjoy these good drenches that are spaced with enough days to dry them out completely before the next watering.  They prefer this mode of watering more than if they were gingerly and very lightly watered only.  The sensitive root hairs  (which are responsible for absorbing moisture and nutrients for cacti) simply go limp and die out if these don’t get enough water. 

The major scourge of Ariocarpus (and cacti in general here in the Philippines) is the dreaded scale insect (not really an insect but a sap-sucking pest which can be likened to our bloodthirsty mosquitoes!).  If not contained, these scales will proliferate and engulf a plant.  I find Ariocarpus that have been badly attacked by scales to have little or no chance of survival.  But if caught early, these pests can be easily destroyed manually, without the use of chemicals or other insecticides.  I don’t like to use harmful chemicals anymore (because using these chemicals is probably taking hours, days, maybe even months out of one’s life).  My good friends, the Purificacions, who are among the very best growers of all sorts of plants worldwide, recommended a white oil-based product, which is harmless to humans but deadly to scales and their allies.  I have used this product now for the last year with very good results.

There is only one species that is not depicted in this article today, A. confusus, a retusus-looking species but with a magenta flower.  I have the plant but it wasn’t flowering when I took the photos.  In fact, it is now the only Ariocarpus species I have yet to flower.  Will keep you posted if and when I am successful.