I don't know much about it but a wick system. The plants will take in the water whenever its needed.

I would look into the wicking system too, or do what I do, and bribe friends. ;)

My parents used to go on a 2-3 week vacation every year, so my Mom would get giant trash bags that are clear to put them in. She'd water all the plants, then put them in garbage bags (as many plants as would fit in each bag), close up the bags with twisty ties and set them next to the windows. When they got back the plants were fine! Worked like a charm every year.

If you do what gardenfanatic suggested just make sure you don't put them in direct sun. You don't wanna cook your plants!!!

Put an old towel in your bathtub, put your plants on top without saucers and put the faucet on a very slow drip then pull the curtain. If you have the right sort of pots, the water will wick up or you can add a wick to the bottom of the pot before putting them on the towel.

The glass watering globes. Water plants thoroughly and then insert a couple of filled watering globes before you go.

For a houseplant a thurough watering is all that they should need before you go on a up to 2 week vacation this time of year still chilly and turn the heat down in your house b4 you go. I would not trust or run a large humidifier without someone present

The towel in the bathtub method has always worked for me.

Wet towel? I am taking notes for my next trip. :)

I agree that turning down the thermostat (depending where you live) is a very good strategy. Can easily extend your watering cycle by a week or more if low enough.

You have a couple of options - reduce the light (so the plants use less water,) or provide them with enough water to last 1 - 3 weeks. Herbs and flowering plants need a lot of light, so setting them in the bathtub may not work for them, although it should be fine for the ferns.

You can set your plants up with self-watering systems, which may mean less work for you even when you're home, since you won't have to be watering every few days.

Or if you like the way you're doing it generally, try this: When you get ready to go away, move the plants away from the windows 2 or 3', and set each of the pots in a dish. Water your plants, and allow a runoff of 2 or 3" to build up in the drainage dish. You'll just leave the water there, it will provide the moisture for the soil. When you come back, remove the plants from the water (if there's any left,) and allow the soil to dry out enough so that it is barely damp, or however it usually is when you water normally. The plants will not be harmed by sitting in wet soil for a couple of weeks. This is basically what happens with self-watering systems, unless you have one of the sophisticated ones that have moisture sensing devices that release water only when the soil is dry. Roots don't "sip" water when they need it - they're little gluttons, and will suck up whatever is there, for as long as it's there.