Hi David, I also have container toms and some in the ground (all started from
seed) cozied up to watermelons.
The ground crop was set in home-grown mulch mixed with 25% Miracle-Gro Moisture Control (MGMC) (avg $10/per huge bag at Wal-Mart). I admit the ground crop is more lush and each of the 5 has healthy clusters of green toms. The patios were planted in straight MGMC in clay pots and so far, none have bugs or disease. Patios are starting to get blossoms. All get about 4 hours full sun daily.
Like Loveapples, this is my first year
growing them. I chose MGMC because it was new on the market and indeed, it has these little balls of water that keep the soil moist between waterings.
I also used MGMC to renew tired soil around garden
plants/shrubs and they responded well, including perking up some daiseys I didn't even know where there! This is just my experience, hope it helps
Tomacco