I don't spray any of mine but always when I am out looking at the spring foliage I squash as many aphids as I can while inspecting the new shoots. It won't wipe them out but might help to tip the balance between the predators (insects and birds) and the sap sucking *fools*! Found the first caterpillar of the year today. It was the type that bind some young emerging leaves together to form a nest. Squished.