Plants grow by a very complex proc­ess. The leaves, which are above the ground, take in some of the nourish­ment that the plant needs by absorbing sunlight and turning it into chemicals. The roots, which are below the ground, soak up minerals dissolved in water, these minerals coming from the soil in which the roots grow. A plant never runs out of sunlight, but the soil does run out of chemicals. Source: Free Articles from ArticlesFactory.com