When you place a bean with a moistened cotton ball in a sealed plastic bag, you've created the perfect environment for the seed to germinate. The cotton brings the right amount of moisture to the seed, and the plastic bag helps to lock in the moisture created by the cotton. Place the bagged bean and cotton in a warm area and the seed will thrive.
When you plant a seed in soil it's easy to overwater because you can't see the exact amount of water you're pouring into the ground. The bean can rot before it sprouts if you give it more water than necessary. By putting the bean seed in a bag with cotton you avoid overwatering because the moistened cotton is doing the watering for you.
Germinating your seed in the cotton not only gives your bean seed everything it needs. It also requires less work. When you plant a seed in soil, it needs a full day of sunlight to sprout, but when you place the bean in cotton, that step is saved. It doesn't matter if your bean is in light or darkness. As long as you have your seed in a moist cotton ball inside a sealed plastic bag, it will sprout.
The cotton in the bag will keep your bean thriving until it has sprouted. A sprouted bean requires sunlight and soil. After the stem has emerged and grown at least an inch, remove it from the bag and plant it in the garden or a pot.
The bean-in-cotton method works with any type of bean; however, lima beans, pinto beans and green beans are among the top choices for many people. If you are growing something other than beans, this method works for other seeds as well.
Another method that allows you the same easy, and near error proof sprouting of a seed is to place the seed into a jar that has been filled with damp paper towels. Fill the jar with moistened paper towels, place the seed into the jar and securely place the lid. The jar and moist paper towel create the same environment for the seed to thrive, while still allowing you to keep an eye on the progress your seed is making.
This method is not only fun for you, it makes a great hands on learning lesson for school age children to learn about the germination and growing process a plant goes though. It also allows them to have a firsthand experience at witnessing how and where their vegetables come from, which will in turn given them a deeper understanding and appreciation.