need help on M. matanzanus

[KNME]

i'm not sure what's wrong with this poor guy
there are 3 possibilities for me scorch damage, overwatering, or drought...
also, the whole cactus is starting to yellow and the discolored part is soft
i really feel bad right now i've had this guy for almost a year now...

[Steve Johnson]

i'm not sure what's wrong with this poor guy
there are 3 possibilities for me scorch damage, overwatering, or drought...
also, the whole cactus is starting to yellow and the discolored part is soft
i really feel bad right now i've had this guy for almost a year now...

Wow, I'm sorry to tell you this -- but I think it's rot. And I really am sorry, because matanzanus is a hands-down favorite among us Melo enthusiasts. From what I see in your photo, it looks like you've been trying to grow it in a heavily organic compost that's way too rich for the plant. If I'm right, the best you can do is learn from experience and try again with another matanzanus using a more leaned-out mix. If you tell me about where you live, maybe I can help give you some ideas. Definitely not for beginners, but no reason to give up with some proper guidance.

[Saxicola]

What Steve says! I just wanted to add that one thing that makes Melocactus a bit trickier to grow is they come from the tropics (places like Cuba), so they get much more cranky about cool winter weather than the typical cactus. Mine survived ok outside last winter, but now that I have a greenhouse I moved it in there for this winter and it seems much happier. For comparison of my dozens of cacti, the only other one I grow in the greenhouse is Uebelmannia pectinifera.

[KNME]

i live in the philippines and the substrate i used was the same mix where it grew on...
i really hope there's still a chance for it to survive...

[Saxicola]

Well, there goes my temperature theory! Your temps should be ideal for this guy. Is it protected from the rain? My friend in Thailand has trouble with a number of succulents because of too much rain. I suspect the cause of the rot is the roots stayed too wet for too long. My gut feeling is this one will not survive, but since I'm hardly infallible and it costs nothing to wait and see what happens, you may as well try to save it. I guess I should explain what Steve and I are seeing. Those dark soft areas are a sign that most of the center of the cactus has turned to brown rotten mush. It is probably too high up in the plant to be able to cut off the top and root it, which is what you can usually do in columnar cacti.

If you want to try and save this guy, or for your next plant, repot it in a low or no organic mix. If you can get pumice use that, if not scoria (lava rock) is good. Keep it out of the rain and don't water this plant at all for a long time. A new plant of it can be watered somewhat regularly but should never be soggy or wet.

[KNME]

how often should i water my melocacti?
i keep mine inside my room beside a window and are totally safe from rain...

[Steve Johnson]

how often should i water my melocacti?
i keep mine inside my room beside a window and are totally safe from rain...

I think your year-round temperature conditions are pretty much ideal -- similar to Cuba, except you have more control over watering since you keep your Melos protected from rain. Even so, I still believe your problem is retaining moisture in the mix too long. I agree with Saxicola, pumice (if you can find it) or scoria should lean out your mix nicely. Although I don't know your setup well enough to know for sure, my guess would be watering once a week. I should also mention that I'm no fan of organic materials in a cactus mix, but you may not be able to get away from it entirely. Too much organic stuff can promote root rot, so look for a sandy loam soil that's light on organics -- once again if you can find it. This is the only advice I can give you, so...

Best of luck!

[KNME]

okay thanks so much steve and saxicola i'll keep those in mind hopefully my other melo's will grow better

i'll be searching for better substrate ASAP

[Saxicola]

Ok, I think I have a pretty good idea of the exact problem now. Half of it is the soil mix we talked about. The other is you are growing it inside. That is probably too dark. If you have a way to grow it outside but protected from the rain that would be best.

[coltonschultz]

One thing that I've heard and seen from multiple growers of melocactus is to put them in shallow pots. They should be wide enough, but not too deep. This way they can drain out well and you won't need to worry so much about watering

[orion]

Sorry for the late response KNME, if you bought this plant from the Baguio growers then you should repot it as soon as possible -- they grow their plants in a medium composed of leaf mould and top soil, and in a very humid environment and somehow that works for them -- into a more inorganic/mineral mix.

Mac