Others hitch a ride in water currents, like pussy willows or cat tails. They're known as floaters. Still others are eaten by animals and birds and later deposited in their droppings. Once planted, there are at least three major factors that determine how well a seed grows. They are soil type, moisture, and sunlight.
Plants can usually adapt to a wide variety of soil conditions.
The best soils retain moisture and are high in something called Humus. Humus is decaying plant and animal materials, things like rotted leaves and insects. Plants can also adapt to sunlight. Those that grow in a meadow have adapted to much brighter light than plants growing on the floor of a forest. Here's an experiment you can try at home that shows how important light is to the growth of a plant.