Today’s plant for #WildEdibleWednesday is Quercus Rubra, or Red Oak. Like its brother Quercus Alba, the White Oak, which we covered a few months ago, Red Oak is among the royalty of the forest. Tall, strong, and regal, red oaks grow to between 100’ to 150’ tall, with trunk diameters of 3’ to 4’. Historically, oaks symbolize royalty or authority, hence the use of oak leaves in U.S. military officer’s rank insignia to this day. In our area, there are two distinct subspecies of red oak – Northern Red Oak, and Southern Red Oak. There are also several species such as Black Oak and Turkey Oak which fit roughly into the classification of red oaks – meaning that for all practical purposes, they are functionally the same.
What’s the easiest way to tell red oak species from white oaks and their kin? Without over-simplifying, white oak species generally have softer, less waxy leaves with rounded lobes that turn brown this time of year. Red oaks have stiffer, shiny leaves with pointed lobes that turn a brilliant deep red in the fall. On both northern and southern red oaks, the bark is gray, fissured, and rough. The bark of the northern red oak is has an almost striped look, with black and gray alternating lines. Southern red oak bark is more uniform in color and knobbier. Southern red oak leaves are smaller (4”-6”) and are more deeply lobed, whereas northern red oak leaves (like the one in the photo) are larger (6”-8”), and have smaller lobes. The red oak gets its name from its ruddy-brown heartwood – evident to anyone who’s ever split it.
Like any other oak, red oak wood is prized as a building material for its toughness and durability. Historically used for beams, railroad ties, support posts for load-bearing walls, tool handles, and wagon chassis, red oak is now mostly used for hardwood flooring and cabinets. For those of us in the bushcraft world, oak is useful for anything requiring a great deal of strength. It excels for shelter frames, stump vises, chopping blocks, and batons. Keep in mind however that it is extremely heavy and hard to carve. Be prepared to sharpen your knife or axe regularly. Red oak is also prime firewood, although it has to season for nearly two years to be at its best. It burns hot and long with little smoke, and makes great cooking coals.
So, why are we talking about red oak as a wild edible? Well, remember when we discussed white oak back in September? If you recall, we said that white oak acorns were the best acorns to eat if you plan to eat acorns. They fall early, they have low tannin content, and they’re typically the sweetest acorns. This is good and bad. They are far easier to prepare and eat, but for this reason, they typically get cleaned up early in the fall by deer, bear, turkeys, squirrels, and all manner of other critters. Their relatively low tannin content also makes them a prime target for worms and grubs. By late fall and early winter, they are often all but gone in areas with rich wildlife populations, and the ones remaining are wormy or moldy. Red oak acorns on the other hand, taste terrible. They have a very high tannin content and thicker shells. This means that although wildlife will certainly eat them, they’re not prime fare. Insect larvae also tend to leave them alone longer. For these reasons, the can be relied upon as a survival food source well into the winter. In the cold, dark days of late fall through early spring, they can provide an invaluable source of protein, fats, and carbohydrates that can be very difficult to obtain otherwise. The nutritional breakdown of red oak acorns is similar to white oak - 50.4% carbohydrates, 4.7% fat, and 4.4% protein. To eat, fill a pot about one third full of skinned, crushed acorns (Red oak acorns contain too much tannin to boil it out of them if they’re whole) and about twice that much water. Boil until the water looks like tea. Change the water and repeat until the water runs clear. The acorn crumbles can be eaten whole, but are best pounded into a flour for making breads and thickening soups. The crumbles can also be roasted, boiled, and used as a coffee substitute.
Medicinally, red oak has many of the properties associated with other tannin-rich trees. Used in a decoction, the inner bark is a fever reducer, pain reliever, and expectorant, making it great for dealing with coughs, colds, and fevers. It can also be used to treat digestive difficulties such as diarrhea and chronic dysentery. Brewed stronger, it serves as an emetic to induce vomiting. The leaves have natural insect repelling properties, and can be used as a leaf bed for shelters to keep bugs away from you while you sleep.
It could be argued that red oak is one of the trees that built America. It was oak that provided the timber for the U.S.S. Constitution and the rest of the Continental Navy, the crossties of the Transcontinental Railroad, the tunnel bracing for the mines of the Gold Rush, the wagon wheels and chassis for the westbound pioneers, and the beams for countless thousands of barns, houses, and churches across America for over two centuries, until the advent of modern building materials.
In fact, as we celebrate Thanksgiving tomorrow… we should take a moment and remember that it was probably Indian-style acorn bread that the Separatists and Puritans of the Plymouth colony broke together with their Wampanoag allies in the very first Thanksgiving feast… a celebration of the American power to PREVAIL against all odds.