A monthly calendar highlights the best days for planting and other gardening activities.
Harris said the current boom in lunar gardening reminds him of the time organic gardening began to find a niche during the "hippie craze" of the 1970s. "They were the first people to bring in organic gardening. Everyone laughed at them," he said. "Now people will pay a premium for organically-grown produce."
What the moon gardening movement currently lacks is a body of modern scientific work that validates its benefits.
John Teasdale, director of the U.S. Department of Agriculture's Agricultural Systems Laboratory in Beltsville, Maryland, said he is not aware of any research on the lunar influences on agriculture, though he said an experiment could be established.
"We know that the moon influences some natural phenomena such as tides," he said. "I would guess that a simple hypothesis would be that lunar cycles could influence meteorological cycles which in turn could influence crops."
Michael Jawson, another researcher at the facility, said the reported benefits of moon-gardening practices are most likely indirect effects that stem from gardener's attentive care. "The indirect effect could be one simply of overall better management because of being careful to do good practices at more optimum times in relation to plant growth cycles," he said.
One tangential relationship between the moon and agriculture was investigated by researchers at the Agricultural Research Service's National Soil Tilth Laboratory in Ames, Iowa.
In 1995 Douglas Buhler and colleague Keith Kohler conducted experiments that showed weed seed exposure to light enhances germination for select species.
Kohler said their findings indicated that till soiling (which brings buried weed seeds to the surface) in complete darkness, such as that under a new moon, hinders the germination of certain weed seedsresulting in fewer weeds in one's garden.
"Certain species, even if they receive only a flash of light, tend to break dormancy and basically turn on the sequence of germination and establishment," he said.
Kohler cautioned that the research implies any light source, not just moonlight, could produce this effect and only indirectly relates to the lunar cycle. Kohler also noted that scientific research directly related to the lunar cycle is sparse.
Meanwhile, Harris said he conducts his own experiments. Each year he cultivates a selection of crops in opposition to the best practices of moon-gardening methods. Crops planted according to the lunar cycle fare much better, he said.
"I've got a large area in potatoes. We've got some planted at the right time of the moon and some crops at the wrong time of the moon. The difference is so obvious and there for everybody to see," he said.
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