Full moon, and Holy Week...almost time to plant your potatoes:
Tradition has it among those who regulate their planting according to "the signs," that crops growing under the ground should be planted during the period in which the moon is waning. A more specific tradition says that potatoes should be planted on Good Friday. A little thought discovers that the two traditions converge. Since Easter is the first Sunday after the first full moon after the vernal equinox, almost invariably Good Friday must fall early in the period of a waning moon. And the vernal equinox is about the earliest time in temperate latitudes anyone would think of planting potatoes.John Festus Adams, The Epicurean Gardener (pub. info here).