Most believe cacti and other succulents can withstand the most intense rays of the sun. But that is simply not the case at all times. True, plants that have been weaned under good light conditions and which have good, robust root systems and enough watering are in the best shape to withstand (and even thrive) in the kind of heat we’re experiencing right now. But sometimes, as is the case with two of my Turbinicarpus pictured here, a sudden intense blast of sun rays can burn the plant and disfigure it for years. The scorch marks on my Turbinicarpus roseiflorus and T. swobodae, which appear as whitish-colored spots on the plant with the underlying epidermis caving in, will take at least a year or two before the plants outgrow them. So these unsightly blemishes will be around for a while….shucks! Peter Bangayan told me he had some precious succulent seedlings literally burn and die from the sudden intense sun.
I was talking to my good friend Paqui Ortigas a few days ago about this crazy heatwave. He told me he was in his chopper one day and the temperature reading was at 40 degrees celcius! Paqui used to grow orchids (he probably still has quite a number in his gardens), and he gave me a few tricks on how he cared for his orchids during intensely hot weather. It was good getting Paqui’s viewpoint on this topic. Wish I spoke to him before my plants burned!
Sometimes, though, goodness can come from a bad situation, if you have the right attitude to handle the predicament. Let me relate the tale of one of my poor Haworthia semiviva ("semiviva" means half-alive or half-dead, depending on your point of view or outlook on life…I prefer the former description myself). Well, I had this plant growing in semi-shade in one part of my house where it was growing fine. It only received afternoon sun in this part of the house. Then I decided to repot it and move it to the other side of my house, which receives sun from early morning to mid-afternoon. I thought the plant could withstand the additional hours of sunlight. Boy, was I grossly mistaken! Two days after the location switch, I noticed the leaves on the whole top part of my plant turning a sickeningly whitish yellow, limp and looking like stewed cabbage leaves. True enough, the plant was very badly burned.
My heart sank when I saw what happened. But if I let the negative aspect of this situation get the better of me, I might’ve tossed the entire plant into the rubbish bin and given it up for dead. Fortunately, I decided to behead the plant instead. I cut off the burnt top and all the cooked leaves and placed the plant in a shadier location. I watered the plant just like any other in my collection. As you can (maybe barely) see from the photos, the cut portion on the top of the plant calloused and, just a few weeks after the burning and beheading, the plant has begun to sprout new life – four new heads have formed and should produce either a multi-headed version of a very hard-to-propagate rarity or, if I cut up the new heads, I could produce four new plants!
Beheading is one way of propagating those hard-to-propagate species, which take forever to grow from seed and rarely, if ever, produce offsets. Depicted in the other photos are a few more shining examples of this beheading propagation method. In the first two cases, I chopped off the top portions of a Haworthia decipiens v. virella and H. arachnoidea v. setata because I wasn’t too happy with the way the original plants were growing. And I also wanted to propagate these usually solitary plants at the same time. The net result for H. decipiens v. virella is I now have a very healthy new plant which was once the top half of the original plant; plus the bottom part has now produced four new heads, each of which will eventually be propagated into four new plants! The second case with the H. arachnoidea v. setata has yielded very similar and successful results  the beheaded top was replanted and is now a sturdy new plant, and the bottom half has been forced to produce four new offsets from the top to the bottom.
This beheading process can also be used quite successfully with cacti. The two examples here are from the collection of Anna Purificacion Conde, showing an Austrocephalocereus which was cut and forced to branch, and a Gymnocalycium species where the growing point was damaged but, with perseverance and correct care, new heads have been produced.
If you perform this operation, remember a couple of things: First, for the severed top part of the beheading, make sure the cut portion has been thoroughly dried and calloused before you plunge it in your growing mix. I suggest a minimum of two weeks, sometimes three, before you plant the top. This will give ample time for the wound to heal and callous. Keep the head in a bright but shaded, airy location during this two-three week process. When you finally pot it up, don’t water immediately. I wait about a week more before I start watering. If you plant the head while the wound hasn’t dried or calloused enough, the head will rot and turn to mush very quickly.
And second, for the bottom part of the beheading, don’t water into the cut/wound of the plant. Just water around the plant, and allow the cut surface to callous as well before letting water get in contact with the cut. If you wet the wound before it properly callouses, you’ll have a pile of much fairly quickly as well.
And as for the burning sun nowadays, make sure your plants are well-watered. Newly repotted plants shouldn’t be placed in full sun until after these have had a chance to produce new, good roots (a process of about two weeks). You can also cover your plants with some protective material such as white nylon mesh, cheesecloth, or even an old piece of white (not dark) curtain cloth, particularly during the hottest times of the day (noon to 3 p.m.) if you want to be extra careful. Just make sure to remove this protective covering when the direct sun’s rays are gone, so your plants will get used to brighter light again.