Hi Diane,We live in a town that loves its trees,but thru a pain staking process that includes parking in the sun on these 100 degree days,I have made a mental list of the tree sap offenders.Silver Maple,any conifer or pine tree{cones too!},Fruitfull mulberry{yes},and some type of alder that literally leaves a greasy patch half circle on the black pavement,oleander shrubs in tree shapes.These trees seem to literally 'weep' either in the process of trying to sweat or as a result of being attacked by bugs.Our city did release mini wasps to fight white flys so at least you can park by the ash trees now,oaks,fruitless mulberry,liquid amber,and chinese pitachio are winners.