My San Marzano tomatoes are doing the least well, and the fruits keep getting this dark staining on them that starts to look like a black powdery fungus.
Thought it might have been a recent hot spell so I pruned the first lot of affected fruits, but the problem has reappeared despite relatively milder weather.
I do not believe I am underwatering, I have three tomatoes in large pots I hand water every other day, and none of the other plants are presenting issues. The soil still feels damp and the pots are mulched.
Perth, Western Australia based. Please help!
by Mondkohl