Yellowing leaves on mountain laurel ?

Two years ago, I planted 3 mountan laurel bushes, about 8 feet apart. All three get the same watering, fertilizing, and sunlight.
The middle bush has leaves that are yellowing. Perhaps a 1/4 of the leaves are yellowing. The other two look great !!
Any ideas why this is happening ?
Thanks for any help !
James
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Vole root damage ?
Bill
--

Garden in shade zone 5 S Jersey USA


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.