Q. Why are only the lower part of some leaves opening? The tips remain closed. It's a BoP tree
Our volunteers who answer gardening questions will address questions related to plants growing in the Mid-Atlantic region. We do not have resources here to answer questions about plants that grow in other parts of the country.
Since you live in Arizona, I suggest you contact the Desert Botanical Garden in Phoenix. In particular, I suggest contact the librarian there via email at email@example.com
Hope this helps!