
Dormant season; lindens take heavy pruning better than most species, and the recurring billable job is clearing basal sprouts, which basswood throws from the root collar every single year. The trap is shearing a littleleaf linden's dense pyramid into a lollipop — the correct work is thinning competing leaders out of the top while the tree is young, because its tight upright branching sets up included-bark forks that show up 30 years later as a split.
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.