Drip irrigation with mineral water bottle is an easy way of watering plants. No cost involved in making this. No power or piping required for supplying water. It is very easy to make. Take an empty mineral water bottle. Then make 4 or 5 small holes
Drip irrigation- I do this every year and it works great! Especially during a long Texas drought- less water waste. The only thing that kept my plants going, and once the plants get growing they hide the bottle.
In addition to recycling plastic bottles and jugs for watering slowly, try to recycle your waste water for the garden. Water collected in rain barrels, or water from the bath or laundry can be used in the garden. I'd probably use glass bottles.
How to make a Sub-Irrigated Planter. I'm not sure I would use a two liter plastic bottle though. Over time I would fear the plastic breaking down enough to poison the plant. Perhaps a wine bottle instead.
Gardening: Controlling Leaf Eating Pests 7 cups filtered water Tbsp dishwash liquid cup olive oil (original recipe calls for canola but I am not putting that GM crap on my food!) cloves of garlic, sliced or minced 1 Tbsp red pepper flakes