Plastic bottle irrigation - Something I tried a while back but not quite the way I did it. Drill a hole in the cap, cut the bottom off the bottle, bury the top of the bottle near the roots and add water regularly.
The narrow necks of wine bottles make them perfect for slow-release watering in your potted plants. Water the plant thoroughly, then fill the bottle with water, place your thumb over the top, invert and press into the soil. good for short holidays.