Trees provide several sources of nourishment in the winter wilds, but they generally require more processing than greens and are not as palatable.
However, edible barks, roots, and saps are highly nutritious and have saved lives in survival situations. (For information on wild greens of winter, see Edible Green Plants of Winter.)
- Tree Barks
The barks that provide nourishment include pine, sweet (black) birch, spruce, hemlock (the evergreen, not the poisonous plant), and slippery elm. The edible portion is the inner bark, the soft, living layer between the protective outer bark and the hard wooden core. The inner bark is paper-thin, so a large surface area is required to provide a meal. Slippery elm bark peels away easily from the wood, and then the outer bark must be peeled from the inner bark. In the case of other trees, it may be easier to scrape off the outer bark first, then the inner bark. If possible, use a thick branch as your bark source to avoid injuring the main trunk. If it is necessary to use the trunk in an emergency, be sure not to girdle (cut all the way around) the tree, which would kill it.
After peeling, the inner bark is dried, a process that usually takes only a few hours, especially if it is hung in front of a fire. The bark may then be ground into flour and mixed with bread flour or made into ash cakes, which Tom Brown describes as “flattened, pancaked dough laid on the white, hot wood ash of campfires, turned frequently to cook evenly”. The inner bark may also be simply boiled and eaten for an experience in bad-tasting survival food; sweet birch comes closest to tasting good.
- Roots
Roots that are frozen in the earth can be thawed by fire, according to Tom Brown. He describes a winter expedition in which his Apache teacher located dried flowerstalks of burdock, dug into the snow nearby to find the frozen root of a younger burdock, and built a fire on top of the root. In half an hour the ground had thawed enough to extract the root for cooking. Other candidates for this treatment might include common evening primrose (slightly spicy), dandelion and yellow dock (both bitter but nourishing). Burdock tastes the best of these. The second-year flower stalks are tall and branching, with the sticky, prickly burrs that attach so easily to fur and clothing, but the roots attached to these stalks are dead by winter. Harvest some first-year roots (look for big, slightly furry leaves without flower stalks) in the fall so you can acquaint yourself with the appearance of the root crown.
- Tree Sap
Sap is a palatable source of vitamins and minerals and can provide pure water in an emergency, although its faint sweetness limits its use as drinking water, at least in the case of maple. Sugar maple trees can be tapped in February and early March, when the temperature goes below freezing at night and above 40 degrees in the daytime. (See How to Tap a Maple.) Untreated sap is highly nourishing, vital, and cleansing to the body, but must be kept cold to prevent spoilage.
Other trees that can be tapped include red maple, sweet birch, hickory, walnut and sycamore. For most of these species, the sap run starts a little later than the maples, in early spring, and they are less sweet than sugar maple.
See also Identifying Trees in Winter and Field Guide to Wild Edible and Medicinal Plants by Tom Brown, Jr., New York: Berkley Books, 1985.
