How to Grow a Bean Plant in a Cup

Learn how to grow bean plants in cups with your kids using simple materials for a fun science experiment.

  1. Gather Your Materials. You'll need dried lima beans or kidney beans (available at grocery stores), clear plastic cups, paper towels, and water. Choose beans that look plump and undamaged - avoid any that are cracked, shriveled, or have holes. Clear cups work best because your child can see the roots and shoots developing. Regular drinking cups are perfect, and you'll want one cup per bean plant.
  2. Prepare the Bean for Planting. Soak your beans in a bowl of room temperature water overnight. This softens the outer coating and helps the bean start sprouting faster. The next morning, drain the water. You'll notice the beans have swollen and may even show tiny cracks where the new plant will emerge.
  3. Set Up Your Growing Cup. Take a paper towel and fold it to fit around the inside edge of your cup, creating a tube that lines the walls. The paper towel should touch the bottom and come up to near the rim. Fill the center of the cup with water until it's about one-third full. The paper towel will absorb the water and stay moist.
  4. Plant Your Bean. Gently slide your soaked bean between the paper towel and the cup wall, about halfway down. The bean should be visible from the outside and held snugly in place by the moist paper towel. Make sure the bean is positioned so your child can see it clearly through the cup.
  5. Care for Your Bean Plant. Place your cup in a warm spot with indirect sunlight - a windowsill that doesn't get harsh afternoon sun is perfect. Check the water level daily and add more if needed to keep the paper towel moist. In 3-7 days, you'll see a small root emerging, followed by a green shoot. Keep the paper towel consistently damp but not soaking wet.
  6. Watch and Record Growth. Encourage your child to observe the bean daily and draw pictures or take photos of the changes. The root will grow downward while the shoot grows upward toward the light. After the first leaves appear, you can transplant the seedling to a pot with soil if you want to continue growing it into a full plant.