Celebrate Winter Solstice 2020

The winter solstice for the Northern Hemisphere occurs on
Monday, December 21, 2020 at 5:02 a.m. EST.

Sunrise over the St. John's River from
Spring Park in Green Cove Springs.

Winter Solstice is the astronomical moment when the Sun reaches the Tropic of Capricorn, which here in the  Northern Hemisphere produces our shortest day and longest night of the year and marks the official start of winter.

At the winter solstice, the sun appears at its southernmost position and at the lowest point in the sky, and its noontime elevation seems to stay the same for several days before and after this day. The sun’s gradual decrease in the sky reverses after the winter solstice and as the hours of daylight become longer, marking what many cultures believe to be a “rebirth” of the Sun.

The term “solstice” is derived from Latin: sol (sun) and sistere (to stand still) because, during the solstice, the sun appears to stand still.

In Ancient Rome, Saturnalia, the Winter Solstice festival, lasted for seven days beginning December 17. It honored Saturnus, their god of agriculture and harvest. To celebrate the coming longer days, their custom was to forgive disagreements, postpone wars, and engage in various festivities. The popularity of Saturnalia continued into the third and fourth centuries. Later Christians adopted some of this pagan holiday traditions as their own. Today's Christmas and the New Year celebrations still include some of  Saturnalia’s customs.

Two store-bought poinsettias held over in a
container placed in an area with no artificial light
 bloomed beautifully just at Winter Solstice.

The plants sense the day length

Plants that are photoperiodic have the ability to measure the number of hours of darkness that occur in a 24-hour period. Plants that respond to a long, unbroken period of darkness are called short-day plants. Winter's longer nights trigger a growth response in short-day plants, such as forming bulbs, blooming or dropping leaves. That's what signals our deciduous trees to drop their leaves in fall. There also are long-day plants that only bloom in summer when nights are short. 

One of the most famous photoperiodic short-day plants is blooming right now--the poinsettias that are triggered to bloom when the nights are long in the fall and winter. Read my article, Poinsettias are NOT poisonous. 

It's a good time to consider how light in our gardens changes through the seasons. The amount of light a plant receives has a profound effect on how well it will grow. Plants vary in their need for light (shade-loving vs. sun-loving), but the those that receive the right amount of light will do better. 

The light a bed receives varies from season to season. There are two main factors in how light in the winter differs from light in the summer. First, of course, is the duration of light changes. Overall, the number of hours of daylight each day is shorter in winter than in summer. Even plants in locations that get sun all day receive fewer hours of sunlight in the winter than in summer.

The second major difference between light in summer and winter is the intensity. The sun stays much lower in the sky during winter. This is because Florida is in the northern hemisphere, and the Earth is tilted away from the sun, which causes it to be weaker and less intense. The shorter hours of daylight and the weaker light due to the angle of the sun are what cause our weather to change and become cooler during winter. Although, because Florida is closer to the tropics than areas further north, these effects on the light are less pronounced.

The other effect of the lower angle involves shadows. Objects cast much longer shadows in winter than in summer. A bed that gets direct sun most of the day in summer may be totally shaded by longer shadows in winter. Also, when deciduous trees drop their leaves, normally areas become sunnier. So, in cases where winter light changes due to either lengthening shadows or deciduous trees, some areas of your landscape may be sunny part of the year and shady part of the year. 

Home-made wreath from wild things in our
yard to mark the season.

As gardeners, much of our success depends on putting plants in the right locations where they will thrive. Matching a plant's light needs to the light a location receives should be factored into our decisions and this is fundamental to good gardening.

 

Winter Solstice Poem

Two weeks before solstice and all through the beds,
Mother Nature wows us with salvia so red,
But hummingbirds all flew south for the season,
Her holiday wishes must be the reason.

No partridges are sitting in my prickly pears,
The plum-colored fruit that this succulent bears,
Could be in dreams with those dancing sugar plums,
Be careful or those bristles could hurt your tongue!

I thought I'd done all of my shopping, but wait... 
Read the rest of my 2006 Winter Solstice poem here.

So I wish you a happy Winter Solstice, Saturnalia, Christmas, New Year's Day and hope that you find ways to celebrate to suit your needs and know that your plants will also be celebrating the longer day lengths.

Green Gardening Matters,
Ginny Stibolt