hegar wrote:Well, your cactus was obviously grown without sufficient light. That is the reason for the etiolated tip. Then some damage occurred to the apex and now your plant is responding by producing offsets. So your Astrophytum ornatum will remain disfigured, because with enough light now the tip will become wider than the narrow part produced when the plant did not have adequate light. What I would do is the following:
I would use that plant for the production of new plants, such as the one formed at the top. Take the largest plantlet off by cutting it with a sterile knife at a point where you do produce the least open wound area. Then you can go ahead and dust the cut end with sulfur or you could apply a rooting hormone that also contains a fungicide. Let the plant rest on its side for several weeks, until it has formed a tough skin at the location of the cut.
After that you can place the new plant in a good cactus growing medium. Do not water it right away though. It should form roots within a month and you then can water it. If the plant part you cut off is too small, your chances of success are reduced, because there may be too much water loss.
The largest of the newly formed outgrowths does look big enough now. Sometimes these sprouting cactus babies do not even need to be cut. They do originate at an areole, which is the same small area that also produces flowers and fruits. So they do not have a large surface area by which they ate held onto by the mother plant. You could try to see, if by just grabbing and twisting the small plant you can remove it. The smaller the damage, be it cut or other injury, the better off you are keeping this plant alive and growing well for you.
One other thing I noticed. Your soil (growing medium) is very dark. You also stated, that you transplanted your cactus into a soil formulated for cacti and succulents. You need to know one thing though. While for example a Schlumbergera or Epiphyllum cactus will do OK in potting soil, you most likely will cause the death of a desert cactus like an Astrophytum, when you place it into the same soil. All three of the names are cactus genera. However the last name (Astrophytum spp.) is a genus that falls into the "desert cactus" category. The first two mentioned are "jungle cacti".
Desert cacti require a growing medium that is not rich in humus and nutrients. The humic acid formed by the break down of humus (compost) will actually cause that kind of cactus to go into root rot. Desert cacti require a mineral growing medium. If you look at the top of this page, there is a tab called "Growing Help" or something similar, which gives you good cactus mixes for desert cacti. I do use coarse sand and gravel that I obtain from our local arroyos (dry creek beds). Because this material does have little water holding capacity, which is good for the prevention of root rot, I do give my plants a weekly watering in the hot desert climate I live in. Also, I do fertilize them a few times during the growing season. However, I apply the Miracle Grow formula with a small N number and bigger P and K values only at 1/2 or 1/3 strength of that listed on the box.
Well, I realize, that I wrote a whole sermon. However, I hope, that you can use some of what I have said.
You most likely will hear from a few other cactus growers, who have more experience growing cacti indoors in pots. I am certain though, that combined, we will be able to help you with your cactus problem.
One more thing: I do notice a few spots on your plant. I do not like the reddish brown larger one at the base of your cactus. Check it, to make sure, that it is not getting soft or enlarging. Then it would indicate, that your plant is rotting and it would most likely fall over then and quickly die.
Harald
Thank you very much Harald. This is really helpful.
I was doubtful of the soil when I bought it. But I just wanted to do something about my cacti (I also replanted a Cereus Repandus Monstrosus using the same soil). I just wanted to give the two cacti something better than what they had. Yes... I noticed that most cacti of the desert looking type I saw on the internet have sand and stones in their pot. I will do the same in future repottings. My healthiest, largest, most successful cactus is (I believe) an Acharagma which I gave a significant amount of sand and a very large pot a few years ago. It quickly expanded into a populous bush - bright green and happy looking.
Speaking of soil, the Cereus Repandus Monstrosus (people on this forum often call it Peruvianus Monstrosus) seems to be enjoying this soil. In just three weeks the branches have thickened and their apexes look like wanting to split into new branches. Overall, it looks like the whole plant is growing and expanding horizontally rather than vertically - a sign of health from what I understand about cacti so far. So I guess that if this soil helps the Cereus like this, it won't kill the Astrophytum (just my inexperienced supposition).
The reddish brown area on the Astrophytum is present on all sides at the bottom, it's not just a spot, but it feels very hard to the touch; just as hard as the green areas. I'm not sure if it's enlarging. I'll have to wait and see.
I must also mention that I live in Eastern Europe, Romania - not the same as your Texas, the homeland of Astrophytum Ornatum. I live in the Western Plain. The region is on the same latitude as Minnesota. Summers here tend to be very hot and dry, winters very cold and moist. But if I were an American living in Texas, wouldn't it be best to just go into the wild and take soil from its natural habitat, from around its most successful looking fellows?
