something happened to my cactus :(

[pitt2015]

Hi All,

I just joined the forum and wanted to ask for help. I purchased 4 cactuses 8-9 months ago and one of them started looking sick from one day to another. He got some white fungus(?) on 2 sides and started releasing water. His shape changed on one side (deflated little). I also just found out that his flowers are fake I'm excited to learn more about cactuses but could you please help me out to answer these questions?

1) what happened to my cactus?
2) can I still save him?
3) do I water them too much? Little over 1oz every 2 weeks. they are by the window, enjoying sunlight for a big part of the day.

Thank you very much for your help.

[iann]

Yes, fake flowers.
1. It may be rotting. Hard to tell, but that doesn't look very encouraging. Is that something white *on* the plant, or is the plant itself going mushy?
2. Take it out of the soil and see what's really going on. Anything rotten should be removed, cut away, until you get back to healthy green flesh. Sterilise before making the final cut.
3. Sounds like underwatering to me, although your plant doesn't look thirsty. Cacti shouldn't be given a dribble frequently. They should be watered thoroughly, then allowed to dry out thoroughly, although that may be difficult with the wrong type of soil which these usually come in. You can sort that out when you find out if there is anything left to re-plant.

This plant, and the one behind it, are etiolated. This is thin weak growth from getting too little light. It could have happened before you bought it. The third plant (Stetsonia coryne) at the back looks OK although the spines are not as fierce as they would be in good sun when it grows up.

[pitt2015]

Thank you very much for your reply.

1. Yes it's actually the plant going mushy like that. I'm going to remove it and see what's on the roots.
3. I think they were not getting enough sun when I bought it. They are on the window with full exposure to sun from early morning until afternoon. I hope they can get better over time.

Is there a one type of soil I could use for all 4 when replanting? Should I replant them into bigger containers?

[spikef35]

100% rot for the mammilaria the old man is just etiolated

[iann]

None of them are really underpotted. The Oreocereus will grow pretty fast and could maybe take a slightly bigger pot. Easiest to tell when you see the roots. Don't use a bigger pot unless the roots are cramped.

Search here for soil threads. Loads of them. About the only thing to say is that the soil they're already in is probably the main reason your Mammillaria is rotting.