Living Marbles

Among the most unusual in all of the plant kingdom is a group of highly succulent plants from Africa called the Mesembryanthemums. This word reminds me of my son Ethan who is always asking me for difficult words to spell. He’s a pretty good speller, although I would think quite a number of young spelling bees would have a bit of a challenge spelling this one. Plants from this group are now referred to as members of the Aizoaceae family or "carpetweeds," but these succulent gems aren’t weeds by any stretch of the imagination, as Johann’s excellent photos depict.

Let me focus on one of the true crown jewels of this succulent family, one of the most coveted and highly collected of these plants, the Conophytums or Conos for short, sometimes referred to as "living marbles." Conos are dwarf succulents that branch out when they grow older, with some of them forming spectacular mats or cushions. Of course, there are species here that remain solitary/single heads all their lives, too. The small heads or bodies are actually pairs of leaves joined at their tips with only a small opening through which the flower stalk appears. Only two highly succulent leaves are produced on each head per year, if the plants are cultured the right way. If you over water them a bit, you may get a result as shown in the photo of C. phoenicium. You will note here that the plant body has split open, and the new leaves are already protruding. This was a result of a bit of carelessness on my part. Plants grown well shouldn’t do this. Oh, well, at least the plant is still alive. The other scenario resulting from overwatering is a mushy, rotten dead plant.

Anyway, the two leaves of conos are united except for a small cleft opening or ridge between them. The white, yellow, violet or reddish blossoms grow out of the cleft. Unfortunately, only two of the plants were flowering when Johann took the photos – C. minutum v. nudum and C. swanepoelianum ssp. proliferans. As I write this article, quite a few more are flowering, including C. tantillum ssp. inexpectatum with spectacular yellow flowers (my favorite color) and C. albiflorum with, you guessed it, white flowers.

The little plant bodies are globular, egg- or heart-shaped; some have small hairs engulfing the entire plant body like C. pubescens; others have rough-looking ridges across them, as is the case with C. angelicae v. tetragonum. The bi-lobe species (I refer to them as "bunny ears") depicted here by C. bilobum ssp. bilobum v. elishae, have larger, more elongated leaves with two distinct tips or lobes. At the tips of the little heads, they may be flat, dentate, notched, dotted, tubercled, or patterned. There is also an interesting variety of plant coloration, from various shades of green to red, orange and violet tinges thrown here and there.

One of my very favorite conos is C. calculus, represented here by its subspecies vanzyllii. Now I know how much we all loved calculus in college, but I must admit, I very much prefer the plant variant a lot more.

Conos grow an inch or so tall, although many in the genus don’t even reach that size. Some heads are hardly a centimeter! Hence, a fairly large and representative collection can be housed in a sunny window sill or a small shelf in a greenhouse. That’s one of the nice things about growing these plants. The plants pictured here are all growing in two-inch square plastic sheet pots. In a relatively small area in my greenhouse, I am able to house well over a hundred plants!

Another reason for my attraction to this genus is the sheer variation among these living marbles. Stop for a moment and look through Johann’s photos here to admire the differences, both major and subtle, across the various species. Based on the latest findings of the world’s renowned cono guru, Steven Hammer of Vista, California, there are about 170 species, sub-species and varieties of these plants. In addition, there are a whole slew of sub-variants, forms and special cultivars as well. There is one hybrid depicted here, C. marnierianum, which is a very rare natural hybrid.

Conos have their growth phases during what is fall and winter in North America and Europe. Here in the Philippines, this would be from mid-August to February, since we’re still located in the northern hemisphere. Generally around the March to July time frame, conos lose their plump form and dry out to a paperlike skin on the outside. Underneath this, however, the new leaf pair for the following year already has been created.

Conos are not quite easy to raise and are a bit tricky. I myself am just a neophyte with these plants, having started to grow them only a year ago. As such, I am still in the period of experimentation. At least that’s my excuse for having killed quite a number of these plants in the process. However, I find them quite fascinating indeed, and their cute shapes and forms just can’t be resisted; so I am going to continue to experiment some more. Suffice it to say for now that this is not a plant group for the succulent beginner, but more for the experienced grower looking for a real challenge. As with a number of other cacti and succulents, conos actually don’t like our very humid tropical environment. They also prefer more temperate, dry climates with cool nights, i.e., the Baguio climate. (I just know these plants will thrive like crazy in Baguio or maybe even Tagaytay!)

In terms of care, the plants should be situated in a sunny, very airy location. During the summer, that’s when these plants rest, and you have to allow them to "dry up". That is, the original leaves have to literally dry up, in order to form the new leaves for the next growth year. If you continuously water all year round, you won’t let the plants do their normal "drying up", and you’ll eventually kill them. Don’t worry if someone comes to you and says your living marbles are dead. They only look that way, but they’re actually fine.

So during this summer rest or "drying up" period, which goes from around March to August or a bit longer, resist watering your plants. Give them more shading during this period, and maybe occasionally mist them when the sun has set. By the way, in their native habitats in South Africa, these plants derive a lot of their moisture requirement from the mists produced by fog (Baguio and Tagaytay ring a bell again?).

In the "winter" growing period, from end of August until February, again water very carefully, and only when the growing medium has dried out completely. In my experience using non-porous plastic as the container, I only water once every two weeks.

Conos are essentially shallow-rooted plants, and during their summer dormancy, much of the root system dries up as well. But if treated appropriately, they will put out new roots when watered in August/September, and the new leaves will burst through the dried remains of the old. The roots of conos are very fine, so the growing medium should incorporate some fine ingredients as well. But the key is for this growing medium to drain water quickly as well. I use a combination of about 50 percent perlite (if you can find the smaller grain size, this would be better for the very fine cono roots), and about 50 percent combination of coconut coir, leafmould and garden loam. I also don’t like to fertilize these plants, particularly with high nitrogen fertilizers, as this may cause the plants to burst. Besides, you want to keep the plants growing as compactly as possible. Repot only when the plants are bursting beyond their pots. I’ll let you know how my "experiments" are proceeding in the future.