I use Bayer 3 in 1 on my roses. I chose not to use it for my trees, because it contains an anti-fungal ingredient. Just my own reasoning, but I didn’t think that would be good for the mycorrhizae and other life forms in the pot. I went with Bonide Systemic Granules. The principal active ingredient is imidacloprid. I have found it to be effective against whitefly, mealy bugs, and azalea lacebugs. I take about a tablespoon, maybe a bit less for small trees, and work it lightly into the soil around the trunk. I’m putting it on as I bring the pots in to get their first fertilizing, and will then re-apply every two moths until winter.