Q.Colocasia Rotting
I overwatered my colocasia and I’ve just realised part of it has rotten. The main part of the bulb (stem? Not sure what to call it) is mushy on one side, extending up to one of the three smaller parts of the plant. The other two parts and that side of bulb are still firm. Any idea if this can be saved an how? Thank you

Certified GKH Gardening Expert
That's in a bad spot! It is likely to infect the rest of the plant.
You might try a fungicide, and carefully changing the soil.
These articles will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/ornamental/bulbs/elephant-ear/growing-elephant-ears-indoors.htm