We learn about ourselves by living on the frontier
Gardener was discussing what could be the cause of Sunflower’s distorted blossom. It might be caused by radiation, cosmic rays, or something from being in the weightlessness of orbit. He thinks this is unlikely. He thinks it is caused by the lack of something in the compost tea or possibly the fungus that causes the brown spots. Maybe it is caused by a combination of all of these. Early explorers would become disfigured or possibly die from disorders such as scurvy caused by what we now know as a simple vitamin deficiency.  This knowledge is pried from the body and stems of those who explore and Sunflower is making his contribution.