It's hard to say what's bothering your plants without seeing them in person, but you could have an insect pest that's not related to your feeding regimen. But, instead of Miracle Gro you might want to use a slow-release granular fertilizer that you scratch around the base of the plants in springtime. Then you are done. There are also some brands that also include a systemic insecticide if you want to go that route. You will find a variety of these products at your local home center such as Lowe's, Wal-Mart or Home Depot."