Tree seedling control

Getting alot of weed calls. 95% of them are for tree seedlings. Most of the seedlings are maple trees, but there are other tree seedlings that have germinated recently. Crabgrass preemergent does NOT prevent tree seedlings from germinating. Due to their woody stem nature, broadleaf weed control not very effective either. However, your lawn mower is the key! Once the seedlings reach a height where the mower will cut off the leaves, they will die after a few mowings. Thanks