potted outdoor yucca
Why are the leaves on my 2 year old potted, outdoor yucca plant covered with white and yellow splotches?
Certified GKH Gardening Expert
It could in fact be a fungus or even pests. They need watering only when the top inch or so of soil has become dry. If the stem (trunk) is soft or has a smell to it, then it could be bacterial soft rot, which will simply kill it as there is no cure. However, if the stem or trunk is still firm to the touch, a fungus infection may be your culprit. Neem oil can help with this, as well as for any insect pests that may be attributing to the problem.