What is the cotyledon, and the first true leaf?

A cotyledon is a significant part of the embryo within the seed of a plant. During the germination process, the cotyledon may become the embryonic first leaves of a seedling to begin photosynthesis. In addition, the cotyledons contain all the seed's food reserves. After using up all the nutrient reserves, the first true leaves will take over the photosynthesis to produce their own nutrients for the plant.

That's why it's not recommended to transplant the plant during the cotyledon stage, since the plant is not producing its own food. Therefore, any damage to the root system, as well as the leaf top could lead to a decrease in plant production later.

Peter Le