For a fun science experiment, kids can grow a salad in a soda bottle and be amazed that they can grow veggies with so little effort. In the picture above, kids at the community garden planted salad greens in their bottles. Kids can grow leafy salad greens in a small space on a well lit window sill planted in a used plastic soda bottle. Kids and their folks can cut a empty plastic soda bottle halfway down into two pieces. Take a strip of old fabric and tie a knot at one end. Remove the bottle cap and drop the long end through the hole in the top of the bottle with the knot on the inside. Turn the top half of the bottle upside down and place it into the bottom section of the bottle. Mark the spot where the bottle top and wick meet the bottom half of the bottle. Take the bottom half and cut a small 3 sided watering and overflow hole at the spot marked on the side of the bottle. Put the top section back on the bottom half and add rich organic compost, packing it in well around the knotted wick. Kids can add water to the soil until the bottom chamber is full. Add seeds or a starter plant and put in a sunny window. The fabric will then wick moisture up from the chamber below and moisten the growing medium. When the water in the bottom chamber gets low, kids can refill it by adding water through the watering/overflow hole. Kids can harvest the salad greens by cutting the outside leaves and leaving the plant to grow more leaves.