Thank you for the photo - it looks very much like scale insects are growing on the stump of your sickly tree. The bumps on the bark look like the sap sucking scale. The best solution for an infestation of such magnitude is to cut the crouton to the ground and let is start again with fresh new growth. Once you see signs of new growth give the plant a feeding with some slow release Osmocote and keep a close eye out for any return of the \"bumps\" on the stem. Then can control the new scale by dipping a cotton swap into rubbing alcohol and wiping off any new outbreaks. Good Luck and Keep Growing, Marianne Binetti