Watering Plants While Away
Begin by watering plants thoroughly. If you like, place plants in large saucers that will hold about 1" of water. This will keep most moisture-loving plants for as much as a week.
Move plants out of sunny windows and into cooler areas of the house. If you have large plants that you can't move, close the drapes so the plants won't be in bright light. Moving plants into low-light areas will reduce their need for water. Group plants by their care needs. Place moisture-loving plants in one area, such as the bathtub. Place plants that require less water together to avoid confusion if someone will come by to care for them.
Make a Mini Greenhouse
You can make a miniature greenhouse for indoor plants from a large plastic bag. Water the plant well, then push tall bamboo stakes into the soil. The bag shouldn't touch the foliage, and the bamboo will keep it from the leaves. Place the plant inside the bag, and seal it tightly with a rubber band or a twist-tie. Make sure the plant is away from direct sunlight. Your mini-greenhouse will sustain the plant for as long as three weeks.
Many commercial products are available to water plants while you're away. Most consist of a reservoir and a wick you place in the soil. As the plant uses moisture, it draws from the reservoir. Also, adding water-retaining crystals to the soil will help plants during dry spells.
Another solution is to fill a washtub with gravel, fill the tub with water just to the level of the gravel, and set a plant on top of the gravel. The humidity from the water will prevent it from drying out. Another method is to set bricks in a bathtub, fill the tub with water to the level of the bricks, and set plants on the bricks.
A gravity-fed watering system provides moisture for several plants at one time. The water reservoir must be higher than the plants. Fill a large jar with water, and set it on a brick. Cut lengths of cotton or polyester rope that will reach from the bottom of the jar to the soil surface of the plants. Place one end of the rope in the jar and the other so it's resting on the soil.