Winter Buds Are Your Friends

Submitted by Paul Hetzler

Every year I teach several winter-tree identification classes. Even though they are always held outdoors no matter how cold it is, student evaluations indicate such classes are generally fun. Showing participants how to tell one leaf-bereft hardwood tree from another is one thing, but explaining why one should bother is trickier. One answer might be, “It’s on the test.” But there are many practical reasons – and a few offbeat and interesting incentives – to know one tree species from another in winter.

From a survival point of view, anyone who finds themselves lost or stranded (or who is hardy enough to go camping) in late winter can get safely hydrated by drinking sap. When temperatures rise above freezing during the day and below at night, sap is available from sugar, soft (red), and silver maples. Maple sap will also flow in autumn during freeze-thaw daily oscillations.

In early spring before the leaves come out, maple sap-flow ends, but birches – white (paper), yellow, black, grey, and river – yield copious sap from mid-April through May. Wild grape vines will give you loads of pathogen-free beverage as well. In fall and early winter, knowing shrub dogwoods and viburnums from honeysuckle may score you some tasty, energy-filled berries rather than noxious ones.

If you’re new at rural living, you could easily waste a lot of time, not to mention run out of fuel wood in winter, if you cut a bunch of basswood thinking it was ash. It’s very helpful to know that in a pinch, one can burn fresh-cut ash and cherry, while other newly cut hardwoods will fizzle out in the woodstove. Plus, you can impress your friends by splitting a round of soft maple with one hand, and then giving them a chunk of elm or bitternut hickory to try their luck. Not that I’ve ever done something like that myself.

Bark is not a reliable feature for ID. It may provide a clue, but is not to be trusted as a primary source. Birches can have black, yellow or reddish bark, for example. Not all hickories have shaggy bark. Cherry and ironwood bark have light-colored horizontal dashes called lenticels, but only on young wood. Some bark patterns, such as the diamond-shaped furrows characteristic of ash, may be absent depending on site conditions and tree health.

A better diagnostic tool is arrangement, meaning whether twigs grow opposite one another on the branch, or are alternate. Most trees are alternates, so we focus on opposites: maple, ash and dogwood, or “MAD.” Shrubs and small trees in the family Caprifolaceae, such as viburnums, are opposite, too. The prompt “MAD Cap” may help you keep track of who’s opposite and who’s not.

Smell is an honest indicator, but only for a few species. Twigs of yellow and black birch smell and taste like wintergreen. Peel a cherry twig and you’ll get a whiff of bitter almond. Soft (red) and silver maple have similar bark, but the twigs of silver maple smell rank when broken.

All our native dogwoods are shrubs, which leaves maple and ash as ther sole members of the opposite-tree club. You’d think that would make things easy, but the stuff which happens to trees can sow confusion. Every twig on a given ash or maple branch might be missing its “partner twig” on the opposite side of that branch. Breakage, pathogens, freeze damage and other things will do that, so don’t trust branch arrangement entirely.

Fortunately for us, buds, like Vulcans, cannot lie. Look closely at a twig to see if the buds are opposite or alternate. Bud size, shape and placement will give further clues.

Beech have long, lance-like buds. Balsam-poplars have sticky, aromatic buds. Red and silver maples have puffy, reddish buds. Sugar maple buds are brown and conical, like a sugar cone. Oaks have clusters of buds at the end of each twig. “Invisible” black locust buds hide under the bark.

Inside each bud is an embryonic leaf (and/or flower). To protect their tender charges, most tree buds have overlapping scales that open in spring. Basswood buds have two or three scales, which vary greatly in size. Sugar maple buds have many, uniform scales. Butternut and hickory buds have no scales. The best winter tree ID tools are buds. Remember that; it might be on the test.

For more details on tree identification, see Cornell’s book “Know Your Trees,” available as a free download (http://www.uvstorm.org/Downloads/Know_Your_Trees_Booklet.pdf).

An ISA-Certified Arborist since 1996, Paul Hetzler wanted to be a bear when he grew up, but failed the audition. Having gotten over much of his self-pity concerning that unfortunate event, he now writes essays about nature. His book “Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World,” is available on amazon.