In mid-winter of 725 A.D., a 52-year-old cleric named Boniface chopped down the great Donar oak in the German territory of Hesse, thus depriving the Hessians of their traditional symbol of the Norse god Odin. In its place he dedicated a fir tree to the Christ child as an emblem of longevity and survival.
That this event was taken in stride by the Hessians was perhaps due to their age-old affinity with forest greenery and the mid-winter festival of Yule and its token log, together with other established means of observing the sun’s birthday at the winter solstice.
Feasts and gift-giving that celebrated agriculture and the end of the calendar year, as well as the start of the New Year, had been carried down from the Roman celebration of Saturnalia. That so much custom coincided with an approximation of Christ’s birth meant that Christmas and earlier symbols were forever wedded.
From a biological point of view, Boniface’s theological substitution of fir for oak doesn’t seem very apt. Firs (and all evergreens) are flowerless trees, somewhat primitive in reproduction and structure compared to an oak, a complex flowering tree.
Yet Boniface was on target. A fir tree is an extraordinary survivor: its coniferous ancestors were among the earliest plants to use pollination as a reproductive method and the first tree species to produce protected seeds.
In cold northern Europe, abundant evergreens provided shelter, construction materials, and fuel to the early Teutonic inhabitants, so a representative of these trees was a logical icon for Boniface to choose – one already imbued with local importance. If he hadn’t been so intent on destroying pagan symbolism, St. Boniface might have converted the Hessians’ belief in the sturdy oak to something more in keeping with Christian tradition, instilling that magnificent tree in European minds as representative of Christ’s nativity at the winter solstice.
His substitute tree existed as little more than an idea for centuries. Greenery of a general sort served simply as decoration during festive times. But in 1539, the first Christmas conifer was placed in Germany’s Strasbourg Cathedral, firmly establishing a convention that has been with us ever since.
Would we be poorer in our Christmas tradition with an oak instead of a fir? Probably. Firs (and many other conifers) have a symmetrical beauty that lends itself to decoration at holiday time. A fir’s conical shape is functional, with tightly tiered branches that shed snow and allow photosynthesis to occur at a reduced pace on sunny days in the coldest months. Young firs are as attractive as large ones, and are quickly grown on tree farms for the Christmas market.
Included in the festive Christmas display of conifers in Vermont and New Hampshire are indigenous species, along with several non-native conifers that are successfully grown here, and even occasionally some cut trees that are brought in from neighboring states and Canada.
We can choose Douglas fir, Fraser fir, or balsam fir – handsome, sturdy trees, outstanding for weighty decoration. White pine is nicely shaped, although its limbs are comparatively weak, and white spruce and red spruce have a disagreeable odor. A few Canaan fir and Noble fir are present, while sparse numbers of Scotch pine probably arrived with Pennsylvania Dutch émigrés.
The best-known feature of conifers is the tiny leaf we call a needle – short, narrow, and tough, with a hard outer cuticle to protect against severe fluctuations in temperature and moisture. Depending upon the species, individual needles may be shed intermittently after a year or two – except those on my Christmas tree that (along with tamaracks) drop en masse.
Firs stand up against winter, but their trunks are softwood, instead of oak’s hardwood. Firs are strong to a point, but rigid and tend to splinter and break when horizontal forces are too great. Oaks are enormously strong and bend under conditions that would shatter softwoods. With millions of slender needles lasting all year long, a fir does an adequate job of manufacturing carbohydrates, but an oak, with several hundred thousand broad leaves that function only during warm seasons, is a veritable photosynthetic powerhouse.
Nevertheless, in December, an open lot stacked with scraggly, leafless young oaks for sale along a highway would hardly attract customers.
Boniface’s choice lives on.
We couldn’t do without Christmas trees. Each year, I look at ours both as biologist and as one who enjoys a festival tree with its bright baubles and handmade trinkets. But just outside on our Vermont hillside – still more lovely, with snow-trimmed branches adorned with busy chickadees, a bright cardinal, and acrobatic red squirrels – are rank upon rank of firs, spruces, and towering pines. They are here for us every season, part of a natural world that cycles year after year, needing no reminder of winter solstice or historical remembrance.