This is one of 3 roughly 2 month old tomato plants. All are showing these gray spot on top and bottom of leaves. If in fact it is a disease, are the rest of the surrounding plants doomed? Any help would be greatly appreciated.
Is This the Beginning of Leaf Spot?
Certified GKH Gardening Expert
They can experience spotting and be completely healthy. If you do suspect fungal infection, I would allow it to dry almost fully in between waterings. On your next watering, replace 1/4 of that water with peroxide. This will kill off anything lurking around in the soil.
It is also good to keep dolomitic lime handy. It will supplement magnesium and calcium, which are common deficiencies in tomatoes.