Indoor plant watering?

Question:How do I make a indoor plant irrigation device while I am on vaction for 3 weeks?
I read somewhere to use 2 liter bottles and rope but I can not find that article.

Answers:
This method sounds like "wicking". You place a piece of cotton rope into a bottle of water and into the plants dirt. The water will soak into the rope and travel to the plant. Bottle should be higher than the plant. It is almost like siphoning gas but the rope serves as the hose and no vacuum is needed.