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First Time Cactus Owner! Moon Cactus Rotting? SOS!

Posted by jrmaine none (My Page) on
Sun, Sep 1, 13 at 22:32

Hello all!

My dad bought me a moon cactus before I moved today and I would hate to lose it!!

The cactus itself is leaning, and the bottom is dry, and has peeled away. It is hollow under except for the stem. There is also one white spot on the top of the cactus. I assume it is rotting.. but just want to make sure before I cut off the top and re plant it. PLease help :)

Follow-Up Postings:

RE: First Time Cactus Owner! Moon Cactus Rotting? SOS!

Well, somebody should do a permanent post on these plants until sanity can prevent the big box stores from hoodwinking people. These and those plants with the glued on straw flowers.

Hi jrmaine. and welcome to GW. What you have is a grafted cactus plant. The top is one species, the bottom is another. The top lives in a desert, the bottom in a rainforest, or at least a tropical forest. The top has no chlorophyll, so it can never live alone. The bottom is usually a short-lived plant, called the stock in grafting terms.

The problem is that you either have to graft the top onto another cactus, or re-root the bottom. In either case, the top will likely shrivel before the roots grow or the graft takes. Actually, a graft would probably cure it, but you need to get to work fast.

The short answer: there isn't much you can do.

The long answer, and you can hit your back button if you don't need more palaver.

The top (the scion) is probably a Gymnocalycium michanovichii, a type of cactus from South America. It is, in its natural form, a nice small plant that offsets readily and makes pink flowers, lots of them. The ones used to produce "Moon Cactus" lack chlorophyll, although sometimes some will revert (seems the red ones especially) and turn greenish and begin to photosynthesize. These can be grown on their own roots.

The stock is usually something like Hylocereus undatus, the same plant that produces "Dragon Fruit" (one word?). It is a plant that has been cultivated for its fruit for so long that the only thing we can definitively say is that it probably originated between Mexico and Peru. In its natural state, it grows very large and climbs trees with the aerial roots it produces in copious amounts.

So you have a small desert plant grafted onto a mammoth climbing plant. This can't be good for long life and good health, and it isn't. Sort of grafting a mouse's head onto an elephant body.

Since you are so taken with this plant, maybe you can find a Gymno on its own roots, or another cactus that appeals to you. The only good thing about the genetic wreck you have is that they are an entry drug, I mean an eye catching way to start growing succulent plants.

RE: First Time Cactus Owner! Moon Cactus Rotting? SOS!

And you did not even mention the absolutely hideous soil that it is planted in. It looks like it is solid water retentive peat moss. This plant was designed to die.

RE: First Time Cactus Owner! Moon Cactus Rotting? SOS!

Oh, gosh, how did I miss that. Yes, the soil should have been my lead comment. Absolutely hideous is a mild term for the soil, is there anything worse, because there is nothing worse than this muck it has, and is indeed the likely cause of the rot. Once wet, it all but excludes any chance any air can get to the roots. Once dry, it turns brick-like and repels water. The final coup-de-grace is the plastic pot.

So the recipe goes like this: graft 2 very different species together. Plant into the most unsuitable medium in a plastic pot. Add eye appeal for the uninitiated. Sell said plant. Wait a few months for the plant to die. The customer will think they did something wrong and attempt another chance to grow one by buying another plant. Cycle is self repeating.

RE: First Time Cactus Owner! Moon Cactus Rotting? SOS!

Here is what one looks like as a blooming normal cactus grown on its own roots And blooming. I did see a photo of a grafted one with blooms the other day. First one ever have that I have seen that gave evidence that a grafted one could grow till they bloom . Floored me. They must have done everything right and prayed for the bugger every night. So it is not impossible . maybe it was grafted on another type of stock like a cylindropuntia stem in the proper dirt.

Well, here is the normal one. You can see that it does make some clorophyl and some of the color is probably due to stress, which they like.


Moon Cactus Rotting? SOS!

Others have been in your boat. Here is what a search pulls up . It might be worth a perusal.

Here is a link that might be useful: Moon Cactus enquiries

RE: First Time Cactus Owner! Moon Cactus Rotting? SOS!

Wait, so the top part can be rooted and survive on its own?

RE: First Time Cactus Owner! Moon Cactus Rotting? SOS!

NO. The top can not make chlorophyl. It will die. It needs the base to live. To put it mildly,even with the bottom, it is a cactus destined to die , just a bit slow than with out the grafting stalk.

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