Watering houseplants when you’re away is always a problem. Even if you ask a friend or relative to water them for you, you’ll probably get home to find a plant or two either forgotten or overwatered. That’s unfortunate, because there is an incredibly easy method of watering houseplants while you’re absent, even when you’re gone for weeks or months!
Simply water the plant normally before you leave, draining any water remaining in the saucer. Remove any dead or dying leaves or fading flowers: anything that will be likely to fall off and rot while you are away (not that a bit of rotten plant tissue will do any harm per se, it’s just that you plant will look better when you return home). Now install the plant in a clear plastic bag: a dry-cleaning bag would be great for larger plants. You could also put several plants together in a large bag. Next, simply seal the bag with a twist-tie and move the plant to a moderately lit spot with no direct sun. The latter point is important: if you put a plant enclosed in plastic in a sunny spot, it will quite literally cook!
Inside a plastic bag, your plant will be able to survive for months without any water at all. This is because most of the water you normally apply to your plants is simply lost to transpiration and evaporation: inside a sealed bag, the humidity level will be essentially 100%. There will be no transpiration or evaporation and therefore your plant will use almost no water.
I can just hear you saying: “Yes, but how will my plant breathe if it’s sealed inside a bag?” I can assure you it will breathe perfectly. Remember that plants use carbon dioxide and give off oxygen during the day. Well, at night, they do exactly the opposite. Yes, that’s right: plants provide all the “air” they need for their own survival. They’re perfectly happy sealed in a plastic bag.
How long can you keep your plants sealed up like this? Easily 6 months, quite possibly up to a year. There are sealed terrariums that have never been opened in decades and the plants are still alive. Eventually, of course, your plant’s growth will be hampered because it will use some of the water and carbon dioxide for its growth, but that will take months or even years. Even if it does occur, your plant will still be in fine shape, just growing more slowly than usual.
Just think! A year of autonomy means you’ll have time to take a world cruise! The truly annoying thing, though, is that generally your plant will be in better condition when you get back than when you left!
One warning: most arid-climate plants (cacti and succulents) will not appreciate the high humidity present inside a plastic bag, but they’re even easier to care for while you’re away. Just water them well, move them back from a sunny window (to slow down their growth), and go off on your travels. They’ll be good for at least 6 months, although they may be looking a bit shrived when you get back.