Good afternoon,

We received your question about your honey locus tree leaves falling off. It appears that your tree may be suffering from Leave Scorch because of our hot dry conditions and a lack of water or in some cases too much water. The following link will direct you to a document about leaf scorch:
https://extension.colostate.edu/topic-areas/yard-garden/leaf-scorch-2-911/

This document provides information about the causes and how to correct the condition. :You will need to determine if the tree is getting adequate water or is being over water.

I am also including information about Fall and Winter Watering which you should do to keep the tree healthy. The following link is for a document on Fall and Winter watering which is important in our climate:
https://extension.colostate.edu/topic-areas/yard-garden/fall-and-winter-watering-7-211/

It is important to keep you trees healthy to reduce stress on the tree to help it grow.

I hope this information is helpful. Feel free to contact us if you have any questions.

Linda, Weld County Colorado Master Gardener