We did have an awesome potted Veggie garden at the last rental we had which we put down to using Wetpot's and Worm castings. Unfortunately We lost our supply of cheap worm castings not long after buying here. As a result the plants never did as well and we gave up gardening for about 4 years. : (»
Knowing what we do now, I think we could give it a good shot and replicate our first results if we gardened in pots with Wetpots again.
Wetpot watering system can be purchased through http://www.productivegardens.com.au/wet-pot-olla-watering-systems/
Please note, I'm not affiliated with Productive Gardens or Wetpots in any way, just think they're an awesome way to irrigate your potted veggie patch.
Have a great One.