Chow_13answered grow question 2 years ago To a scientist, the first law of thermodynamics states, "you can't get something from nothing" and this is one of the single most foundational observations of the universe. According to this concept, the leaves capture light and convert it into sugar which is used as the chemical power source to build the body of the plant, so removing the leaves will remove the power to grow, and thus have a negative effect on plant growth.