Well, that's one way to deal with the soda bottles...

The school ecology club also recycles plastic bottles as planters by discarding the plastic cap then cutting the bottle about a 1/3 of the way down from the top so that the bottle is still standing up as normal. the top 1/3 they fill with potting soil and plant with a recycled strip of a cotton based material hanging down like a tail or wick from the base of the potting soil. Water is placed in the bottom 2/3 of the bottle and the part with the plant is placed inside the bottom 2/3rds so that water goes up the wick to the plant.

As long as water is kept in the base you don't have to remember to water your plant - nice and easy.

Ah, pop plants!