How to Recognise Stem Rot

I decided to write down some notes on stem rot, seeing that I lost 4 plants to this disease.  Whereas in some cases it was my fault due to excessive watering with no drainage among others, I feel I could have saved most of them had I recognised the symptoms earlier.  So here's a small list:

1. Stems begin to lose color - they start going yellowish brown or dark brown just at the base as they are coming out of the soil. 

2. The plant loses it's "vigour", it sort of droops down, slightly at first.  This was one of my mistakes as I thought this was because of underfeeding. Unfortunately, the more water I gave it, the more I aggravated the situation.  Eventually the stems droops down even more until there is nothing left of the plant.

3. Later on in the process as the rotting increases (the dark brown on the stems moves up towards the base of the plant) the plant stops drinking water altogether.  This is the final stage and can take a couple of weeks.  If you notice that the soil remains wet and sort of dries by itself due to evaporation, which is slower, rather than the actual plant feeding you know it's the end.

Stem rot does not affect all stems at once, and it starts at the bottom of the plant.  This means that if you think that the plant has stem rot, stems which are higher up and unaffected (still green and healthy) can be cut and the plant can be propagated anew.  I have never tried this myself because it was always too late, however the plant can be "saved" in this way.

Another way to recognise stem rot in plants with lots of foliage such as my poor portulaca is identifying stems which are drooping down and look unhealthy and giving them a pluck.  Since the base is rotten the stems will come off easily and you can see the brown rot at the base of the stem.

I have also read that the rotting can be cut off from the plant to save it without propagation, again I have never tried this and to be honest I figured that since the rotting emerges from the soil I always thought that the root ball would be severly infected. 

Hope this article helps you to recognise the early signs before it's too late.  This is directly from my limited experience and I am by no means an expert so please take this as a suggestion rather than advice.