Evidence for Lunar-Sidereal Rhythms in Crop Yield: A Review
Nicholas Kollerstrom and Gerhard Staudenmaier
ABSTRACT
In 1956, Thun developed a procedure of sowing according to the position of the Moon in front
of the twelve zodiacal constellations. These constellations were classified into four groups
according to the element (Earth, Water, Air and Fire) astrologically associated with them. Root,
leaf, flower and fruit crops were found to show increased yields if sown when the Moon stood
before Earth, Water, Air and Fire constellations, respectively. Thun’s philosophy of sowing by this
sidereal rhythm has become a major component of biodynamic planting calendars, even though the
founder of biodynamic agriculture, Rudolf Steiner, had only mentioned positive effects of the Full
Moon in an agricultural context. In 1990, Spiess published a three-year study claiming to find
effects of other lunar rhythms but not those of the 27-day sidereal month. This paper reviews
published confirmations of the ‘Thun effect’ and reanalyses data concerning planting times and
crop yields from Spiess’s study with radish and carrots, by computing yield values as deviations
from a moving average rather than as deviations from seasonal trends estimated by quadratic
functions. The re-analysis showed an increase (ca +7%) in the yield of radishes which were sown
in Earth constellations for his 1982 trial, with a comparable result demonstrated on re-analysing
data from three years of carrot trials.