Dig a hole in middle of mound + bury a plastic pot, leaving the rim sticking out a few cms. The earth should be mounded up around the pot, with its rim at the top of the slope. As the plants grow, their roots spread around bottom of the pot. When you fill the pot with water, it slowly drains out of the holes at the bottom of the pot, directly and gently watering the roots. Once the plants start bearing, use the central pot to feed your plants with organic liquid fertiliser.
Source : Vertical vegetables