I am trying tomatoes in containers on my screened in pool surround this year. I am at a loss as providing the correct amount of water. My pots are 20x17 round, with rocks in bottom, drainage holes and wheeled trays. One plant (black krim) seems to be happy. The other (which is about 6 ft tall now) is a small yellow tomato (Iowa species). We are in a very humid climate, and the temp is already in the 80's. Early on, I got fungus fly from overwatering, I presume. I let them dry out, and I check the soil in the a.m. with my finger to about a 2 inch depth. But today, I went out at 4 pm, and the yellow tomato was already droopy. Both are flowering well, both are producing tomatoes - though none ripe enough to pick. I am afraid I'm going to ruin the yellow tomatoes and am afraid to over water due to the fungus fly (no natural predators as in a screened in area).
Correct Amount of Water
Certified GKH Gardening Expert
As they are outside in containers, I would not worry about them being overwatered. They need the water and in 80F+ heat, 2X a day is not too much.
As for the fungus fly, you can treat the soil with neem oil. It will keep the flies away and is organic and non-toxic.