Schefflera rotting from the top
Hi everyone, a couple of months ago I pruned and defoliated a few of my dwarf umbrella plants to encourage branching. One is doing just fine, but the other two started turning brown from the top. One died from it.
The other, in this picture, has sort of scabbed over to stop the disease from spreading-- you can see that the tip is brown and dead, and it transitions almost instantly to a full green trunk. It's done this twice, but the disease came back last time. I'm afraid the plant is still vulnerable, so I've been afraid to cut off the scabbed tip or even water it much.
Any ideas what is happening to them? Thanks in advance!