Just cut open rotten cactus -- follow up questions

[ekcayen]

Hi again,

So I concluded that my cactus was indeed rotten from other online research. It said the cause of rotting would be over-watering and I was initially confused because I had not watered my cactus in at least 2 months. When I uprooted it however, I was astounded to see that there was water inside of the swollen & dead portion of my cactus! The soil was damp as well.

I concluded this water was there from the last time I watered and therefore I must have been using too dense of soil -- next time I should try for some with more peat??

Anyway, I cut off the top part, which was the only part without the rotting and there seemed to be some brown stuff inside. There is a picture attached. My question is, although the top part seems healthy, green, and firm, is this a sign of rotting too? I washed out the brown goop. The picture attached is of the cactus after the washing.

So my questions are --
Should I use soil with more peat?
Is the top of my cactus healthy?
Can I leave the cactus top out until it forms a callous, then attempt to repot it?

Thanks for all your help!

[greenknight]

Less peat or none, not more peat - peat really holds water. Need more grit - http://www.cactiguide.com/article/?article=article8.php

The top might make a cutting, if it's cut clear of all rot (there should be no discoloration, even). Washing out the brown goop won't help, you have to keep cutting until no trace of rot remains. There may not be enough left after you're done, but that's the only hope.

Here's how to root it - http://www.cactusinfo.net/propagation.htm

[ekcayen]

So in my above picture, it's all green around the cut...however 2 hours later it is now brown. Is this ok (a sign of just getting used to oxidation?) or is it a sign of the rot?

[greenknight]

It should not turn brown. Sterilize the knife with alcohol and slice off some more.

[ekcayen]

Thank you for your help -- we did so and there was brown throughout the rest of the cactus. He didn't make it, unfortunately. Thanks again for your help

[greenknight]

That's a shame, just a little too late.