the 2-4D you can spray anywhere you want to kill broad leafs, it wont hurt grass unless you mix it way strong or spray really heavy. Broad leafs includes trees/shrubs/flowers. You can spray around the base of trees, as long as you don't get it on the leaves. If it gets on the leaves of the flowers, they will get toasted as well.
Remember if you spray close to flowerbeds, the over-spray can get them as well, especially if its windy out.