Which slow release tomato plant food?
I’d sprinkle some dry plant food around the roots so it will gradually be dispersed by your watering system. We also have an automatic watering system but the volume of water is totally inadequate for food plants which require litres of water at this time of year, not the dribble that seems to be regarded as adequate for hanging baskets and ornamentals. I’d try really hard to find a friend to mind your plants for you.
