It is not necessary to fertilize American Linden in the spring, that is an optional job best done in the fall. All trees living in turf are stressed because the turf wins out in the battle for food and for water. Ground cover plants or mulch around the base of the tree helps reduce this stress.
In periods of drought, this tree should be watered just as much as other plants in the landscape.
Optional Task – American Linden will definitely benefit from an annual application of slow-release granular fertilizer, however in most landscapes, they will survive just fine without that supplement. If the tree is mulched or has ground cover around its base, it needs no fertilizer. If you do choose to fertilize, then September or October are the months in which to feed trees. Sprinkle the fertilizer on the soil under each tree out to1 1/2 times the distance from the trunk to the tips of its branches (its drip line). The general rule is two cups of slow release granular fertilizer for every inch of diameter of the trunk measured four feet above the soil surface.
Lindens need protection from snow thrown by snow blowers. If they are in the vicinity of the sidewalk or driveway and therefore close enough to be affect, wrap the trunks in burlap, or even better rig a barrier of tall stakes and burlap to protect the tree from the thrown snow.
Winter is the best time to prune this tree. Lindens can handle fairly severe pruning. Trees that have gone 10 or years un-pruned respond to having their main branches cut back almost to the trunk and will rejuvenate over the next 5 to 10 years. Judiciously topped, Lindens can be also trained horizontally to form an aerial hedge. Removal of suckers from the base of the trunk may be required.