A seed is a plant that has not started to grow. All plants were seeds before they started to grow and some seeds grow faster than others. Some plants, like trees, take years to grow but other plants like some beans can take only a few days. An oak tree for example, grows very slowly. This means that you can become a father and a grandfather and the oak tree would still be growing. A seed needs many things to grow. It needs food, water and sun. If it has all these things, a seed will grow into a plant.