Little Leaf Linden Tree Leaves Turn Brown In Mid-July

Question From: A. Blue - NEW YORK
Q: My 12 year old Little Leaf Linden is approx. 20ft tall with a 5” dia. trunk. First 7 years very healthy, all aspects, last 5 years leaves start to turn brown around mid July. Arborist drills holes around root location to add moisture & soften soil. No apparent insects found on leaves. Location Southern Ontario, Canada

A: Sorry, I can't help you with thIs issue.  I suggest you get a second opinion from another certified arborist  or take live leaf samples and close up photos  of a branch and bark from the tree to your county horticulture agent.    Best Nancy and Happy Yardening.