Planting by the Moon: what tradition says and what agronomy measured

The question is worth asking.

What tradition prescribes

The consolidated version that survives in farmer's almanacs and organic gardening books goes roughly like this:

• New and waxing moon: plant what grows above the soil (leaves, fruit). The folk theory is that sap is rising, supporting the aerial part of the plant.
• Full and waning moon: plant what grows below the soil (roots, tubers). Sap supposedly descending, strengthening what stays underground.
• Waning moon: harvest and prune. The argument: plant tissue holds less water, the harvested product lasts longer, and pruning is less traumatic.
• New moon: rest the soil, no heavy work.

Rudolf Steiner's biodynamic version pushed further and split days into "root days," "leaf days," "flower days," and "fruit days," based on which constellation the Moon was crossing. That goes to a level of detail mainstream science definitely doesn't follow.