Don't tell me that is cheap bunnings / supermarket soil? Ideally you should have blended that with plenty of perlite. That barky wood chip stuff seems to hold a lot of water.
How often are you watering? What ferts are you feeding them with? I'd recommend flushing with plenty of plain water then use charlie carp at about 1/2-3/4 strength. After that let the soil dry out almost to the point the plants start to droop. Water/feed them when they dictate not based on a gut feeling. I'd probably water & feed with 1/2 strength once a week given the size of plants vs pots. Keep an eye out for fungus gnats if that soil has been kept too wet too often.