I have a Sweet Million and Celebrity plant growing in an earthbox. The cherry toms, which hosted a lot of fruit worms last month, now has a lot of yellow leaves with brown spots. The celebrity next to it, however, is indestructible.

Therefore, I am not sure whether or not the cherry has been hit with a late blight that the celebrity is more resistant to, or if the worms really did more damage than I thought, or what. While I would like to extend the season as long as possible, it is the end of August, and so am not sure if I should even try to address the damage or not.

Can anyone explain what is going on, and suggest what I should do about it?