Dharma Gardens

At a talk sponsored by area Granges, a local nursery owner was asked about our last expected frost date.  She answered with a somewhat-standard reply for hereabouts: “Memorial Day weekend…”  She cautioned that she couldn’t be certain because she didn’t remember when the full moon was, and that it was common practice in the greenhouse industry to adjust the last frost date as you are much more likely to get a frost the two nights surrounding the full moon.  While I was skeptical (what could the phase of the moon have to do with temperatures, night time or otherwise?), her matter-of-fact/common-wisdom delivery intrigued me, and soon won me over.

When I got home, the first thing I did was look up the May/June full moon: this year it is in the wee hours of the morning on June 7th.  So, by her metric, there is an increased risk of a late frost either on Sunday or Monday night.  That was certainly within local custom: most folks don’t plant out their tomatoes until the second week in June.  Next, I Googled “full moon frost.”  I quickly found that this was a reasonably widely shared rule of thumb.  However, it was also widely considered to be more lore than fact by the scientific community.  While weather sites debunked it only in general terms, they were emphatic that there is no conceivable cause and effect.  Several posited that one was much more likely to notice a full moon on a clear night, and that since clear nights can lead to frosts (no clouds to trap daytime heat) it is easy to understand the association .

Although this mirrored my own initial reaction, I found myself abandoning those articles almost immediately.  There was something I found appealing in the full-moon-frost folk lore that transcended logic and science.  I do not take gardening to be an entirely, or even mostly, scientific endeavor.  Even on the benign end of the scale, it seems that an overly logical approach denies the magic and mystery which amazes me every day in my garden.  I am not even inclined to have my soil tested — I would much rather pay attention to how my crops are doing, to listen to my garden, and nurture the various beds accordingly.

So, although my mind knows that the full moon is unlikely to encourage a frost, I plan to consider it in my schedule — at least on the side of caution.  I will not use an early full moon as a green light to plant out my tomatoes and peppers sooner than normal.  But it still makes sense in my heart to respect the lore and exercise some patience in years like this when at least the timing would be right for a full moon frost to catch me and my seedlings whom I lovingly raised by surprise.

For those who prefer the scientific method to old-timer wisdom, I found an impressively well-researched and reasoned piece on the subject: Full Moon You Say? Frost You Say?.  It makes perfect intellectual sense.  But, for now, I choose to garden by heart.

-John