
The one to get right: a linden skeletonized brown by Japanese beetles in July is not dying — it holds bud and refoliates the following spring, and it takes repeated total defoliation over consecutive years to actually kill a mature tree. Real decline looks different — dieback that begins in the upper crown and is still dead the next May, sometimes with Verticillium wilt streaking in the sapwood or decay at the base of an old sprout clump.
Two different trees ride under one name here: native American basswood (Tilia americana), usually a remnant woodland tree on lots carved out of timber, and littleleaf linden (Tilia cordata), the tidy pyramidal European street tree planted by the thousand in Indianapolis-area subdivisions. Which one you have changes the work — basswood suckers hard and often grows as a decay-prone multi-stem clump, while littleleaf stays single-stemmed and compact but is markedly less salt tolerant than the oaks sharing its tree lawn.