I doubt many of you have every heard the word Phenology.  It’s something that I have always used, as does anyone that works outside.  But I didn’t know it had a name until a few years ago.

In 1995, I became seriously invested in my career as a horticulturist.  I was in school at the University of Georgia, studying leaf buds and bark patterns, able to identify hundreds of species of trees- even as small leafless twigs.

Although most of what I learned in my classes would be defined as hard science, the knowledge that I gleaned from working at nurseries and farms was much more in tune with the pages of the Old Farmer’s Almanac.  Information was shared by my mentors about sowing seeds and tending the earth, when to plant and how to harvest.  My skin was deeply tanned (a regret now that I am turning 39) and I was in rhythm with sunrise and sunset.

I didn’t realize it at the time, but I was learning to farm and garden using a study called Phenology.  It’s the study of the natural progression of life cycle events in plants an animals as they are influenced by seasons and climate.  So, for example, in the Lowcountry, Red Maples (Acer rubrum) will always flower before Redbuds (Cercis canadensis), regardless of whether we have an early or late spring.  The Red Maples may flower earlier that they did the year before if spring temperatures arrive early, but they will always follow a natural progression.

When you read a seed packet and it instructs you to “plant when the soil warms in spring” that is Phenology.  You are following the directive of the earth’s cues rather than a rigid calendar.  And Phenology is as old as agriculture. Nomadic Native Americans used indicators from the flora around them to adjust planting dates for corn.   Instead of picking a date in the spring, they would wait until the oak leaves were the size of a mouse’s ear.  Now, what does an oak tree have to do with corn?  The native oak is responding to the progression of spring- warmer temperatures, warming soil, longer days, rainfall.  This let the Native Americans know that they could plant the corn and it would germinate rather than rot in cold soggy soil.  No matter where they migrated, they could look to that cue for direction.

This cold snap made me think of the one that I have used every year that I have been working in the Lowcountry: the full moon closest to Easter.

For the coastal zone that we are in, March 15 is the “frost date”, or the last day that we can expect to have a freeze or frost in our area. It means that you can safely sow seeds and set out tender plants without fear of losing them to cold temperatures.  Only Mother Nature doesn’t know about our fabricated frost date, and we have freezes and frosts as late as the end of April.

A better way is to look at the full moon following Vernal Equinox.  Spring falls on March 20/21 every year, but Easter fluctuates based on the date of the first full moon after the equinox.  Easter Sunday is the first Sunday after the full moon that follows the equinox (is that clear?).  That means that Easter can be as early as the 21st of March and as late as the end of April.

Farmers hold their breath until the full moon passes that is associated with Easter.  For reasons beyond my education, the night of the full moon (and a day on each side) tends to be still and clear– great conditions to create frost- and the temperatures dip. Over the 15 years that I have worked in the Charleston area, this has held true nearly every year.

And its true again this year.   We’ve been complacent this spring because it seemed to warm up quickly and sustain. We’ve been kayaking and paddle boarding; I’ve even seen people waterskiing in the ICW!  It hasn’t been that typical blustery March that we expect, and yet here we are, the night before the full moon with a predicted low in the upper 30’s.  It will be a clear night, and areas in the outskirts will wake to a light frost, enough to burn the leaves of tender transplants.

I myself am a tender transplant and I had acclimated to the warm days and balmy nights.  You can be sure that Chris and I will make one last fire in the fireplace tonight.  We’ll celebrate the end of winter and the beginning of growth and spring renewal.  And then we’ll expect to see the creeks fill with kayakers, boaters and explorers. Spring is officially here.

See you on the water,
Kari