yuccas in pots
We have two yucca plants in big pots at the front of the house. The tips are getting black burnt with a honey color secretion. The plants have been healthy for two years but unhealthy for six months.
Though the Yucca plants do like to be root bound, it the plant is so root bound and can't take up moisture and nutrients it may be time to repot the plant.
Here is a link with more information.