A colleague who lives in my building told me he'd be off with his fiancée for a while. He asked me to take care of his plant while he was away (I think he's gone until August 13). Since I myself have been traveling to Seoul (I was there last week and am going again, for a few days, as of tomorrow), this made it necessary for me to think of a way to keep the plant alive in my absence. The soil in which the plant sits is very loosely packed; water runs right out of it, which is nice insofar as the plant's roots will never drown in too much water, but which is inconvenient since the loose soil dries all too quickly. My colleague said the plant could afford to "starve" for a day or so; it's wilted before, according to him, and has bounced right back upon re-watering.
Last week, when I went to Seoul, I simply over-watered the plant and left the rest to God. That seemed to work fine, since I was in Seoul for only a few days. This time, however, I'll be in Seoul for the better part of a week, interviewing and teaching, and I doubt the plant can survive too long of a dry spell. So the practical question was and is: how can I make a watering system that will work in my absence? Such a system would have to drip the water very slowly into the plant's pot so as not to flood it. I went online and looked up "dripper for plants," which led to the correct term for such a device: a DYI drip-irrigation system. There are plenty of photos and videos for how to make a DYI-DIS; human cleverness is on full display. After some trial and error, I chose the design that seemed most sensible to me—not to mention simple in an Occam's Razor sort of way.
Behold (hover cursor over image for explanation):
The rate at which the water leaves the soda bottle is determined by how tightly you screw on the cap. Screw it on too tight, and no water will leave at all. Too loose, and you flood your plant. Finding just the right degree of tightness took some effort, but I finally found it, and the system seems to be working well. As long as the plant's soil remains moist while I'm gone, I think the plant will be in no danger of drying and dying.
The Internet is, I must say, an amazing resource for getting things done. It's like one gigantic how-to manual, and has certainly become, over the past couple decades, humanity's brain trust. I needed a DIY drip-irrigation system for my colleague's nine-pound weakling of a plant, and poof—there were the instructions on how to build one.