Red Bud trees -no leaves
Two red bud trees in my yard are about six years old and eight feet tall. The young trees have had leaves until this year - not one leaf on either tree this year! There is no visible fungus or damage. Any thoughts and suggestions are welcome. Thank you!
Your trees sound like they are dead. Once dead it is difficult to determine why. You can scratch the branches with your fingernail and look for green tissue. If you see brown then the branches are dead. Below is some information.
Red bud trees are under story trees and grow best in morning sun and afternoon shade. They like a moist well drained soil and grow well except in really wet sites. Redbuds decline from any type of stress such as drought, poor drainage, too much moisture, mechanical injury to the trunk, planting too deeply, excessive mulch, etc.
Take a look at our publication on these types of problems https://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/TreesandShrubs...
When the trees suffer from the above they become weakened and more susceptible to a canker disease for which there is no control. https://extension.umd.edu/hgic/topics/cankers-trees-and-shrubs
Sounds like you need to replace the trees that match your site conditions and consider mature height and width.