A decision that any gardener faces when going on vacation that most nongardeners may not even think about is what to do with your plants. Plants, particularly indoor houseplants, are completely dependent on manual watering to thrive. While you can hire someone or ask a friend to water your plants, there are many devices that deliver water to plants while you're away.
A drip irrigation system consists of a soaker hose, pressure regulator, backflow preventer and a timer. You can arrange your soaker hose around the inside lip of your containers so the hose will sweat water onto the soil it rests in. Connect one end of your hose to a pressure regulator, timer and backflow preventer. Connect the other end of the hose to a faucet. Set the timer to release enough water to your plants each day.
Place a child's wading pool in a location that receives a little bit of sunlight, but not as much as your plants normally receive. Fill the wading pool with 1 inch of water. Place your plant containers in the water. The water depth is not sufficient to overwater your plants. Instead, they will wick up the moisture through the soil to the roots as needed. By placing the plants in reduced sunlight, you also help lower water requirements. Although some water will be lost to evaporation, 1 inch of water in the pool is sufficient to water your plants for a week.
Water Globes and Terra0cotta Cones
Many garden centers carry water globes and spike-shaped plastic watering systems or terra-cotta cones that attach to 2 liter soda bottles. These slow-drip irrigation systems hold water in reserve for watering your plants. As the soil around your plants dries, it draws moisture from the reservoir. A hand-blown, glass-bulb-type reservoir will water a houseplant for a week in your absence.
Carry each of your outdoor container plants to the north side of your home or place each houseplant in a location where it won't easily receive sunlight to prevent them from using much water. Shove each container together so all containers touch. This helps reduce evaporation of the water in the containers. Fill a bucket with water and place it on a stool above the container plants. Place one end of a rope or string in the bucket of water. Put the other end of the string into each potted plant. The water will wick away from the container of water and into the soil of the potted plants.