Shining the spotlight on a familiar favorite that’s full of surprises.
Awbury Arboretum’s Year of Trees continues with March’s magnificent pick, the River Birch aka “water birch” or “black birch” (betula nigra), a robust and attractive shade tree seen throughout Eastern United States. Visitors to Awbury will find many excellent specimens while exploring 56 acres of native, champion, and heritage trees among ponds, meadows and manicured gardens. This tree thrives in a variety of settings, from creek beds to playgrounds.
While River Birches prefer to grow near water, they can make do with humidity in the air – they’re perhaps the only living organisms who actually enjoy our region’s famously sticky summers. When it comes to bugs and other pests, this tree is basically immune. In fact, River Birch is so robust, it can starve neighboring plants of nutrients and moisture and its shallow roots have been known to crack through pipes, driveways, and foundations.
Wherever these trees grow, they provide shelter and protection for a wide variety of critters that make their homes in its branches. The River Birch is a fantastic source of food, as well. Deer will eat the twigs, buds, and foliage, while beavers will feast on the bark. Birds and rodents consume seeds and flower clusters. Wild rabbits regularly make a meal of tender green seedlings; hummingbirds and woodpeckers feed on the sap of mature trees.
Humans, too, have grown a taste for River Birch, developing a method for creating a sweetener from its sap similar to maple syrup; brewing this with twigs creates a distinctive beverage we all know locally as birch beer. River birch is also host to at least two species of butterflies (Mourning Cloak & Dreamy Duskywing), crucial pollinators for the continent’s flowering plants, fruits and vegetables.
On top of this, River Birch is also lovely to look at! As a tree grows, it fills out into a tall, graceful pyramid shape, its symmetrical branches clad in two-toned, serrated leaves that appear to shimmer in the wind, and in autumn turn a brilliant gold. In winter snowscapes, groves of birches stand like marble columns, their delicate branches frosted into fluffy crowns.
River Birch is a fast grower, too, adding 1 – 2 feet per year, reaching average height at 30 – 40 feet in about 20 years (in ideal conditions, they can grow as tall as 60 – 80 feet). They’ll live a typical 40 – 50 years. These pleasing trees provide welcome shade in city parks and residential landscapes, where they’re popular plantings for public enjoyment.
🌳Birch Tree Fun Facts🌳
- Birch trees grow across the Northern hemisphere, with native species in Asia, Europe, and North America; the oldest known birch fossils were found in Washington State, and date back 49 million years.
- Birch bark has oils that make it both flammable and waterproof. It can be used as a fire starter or come in handy as waterproof paper. According to Thomas Jefferson, birch bark was the best for taking field notes in wet conditions.
- The oldest dated birch bark manuscripts are numerous Gandhāran Buddhist texts from approximately the 1st century CE, believed to have originated in Afghanistan.
- Pollen grains released by the birch tree are responsible for 15 to 20% cases of hay fever in the Northern hemisphere.
- While river birch wood is hard, strong, and close-grained, it is too knotted to be used as lumber, and is instead used primarily for inexpensive furniture, toys, artificial limbs, and occasionally veneer.
- Birches are known as “pioneer species” due to their ability to grow on barren land and in disrupted environments.
- Birch twigs taste naturally minty, and were one of the world’s first toothbrushes (indeed birch aka “wintergreen” oil is still used today in many toothpastes and mouthwashes).
- An astringent from the leaves and bark of river birches is a noted treatment for eczema, and a tonic brewed from the leaves is said to reduce fevers and manage the symptoms of gout, rheumatism, and kidney stones.
- Being one of the first trees to green in the spring, the River Birch has a strong connection to fertility. In Celtic folklore, the birch tree symbolized fertility, renewal and purification. During festivals, Celts would burn bundles of birch trees to drive out spirits of the old year.
- The birch tree held significance during Beltane (now celebrated as Mayday) because of its representation of spring and new life. The trunk of a river birch was often used as a maypole at these celebrations.
More details in author and expert Dan Sardaro’s original article on Awbury’s website, where he provides environmental context and fascinating botany. Follow Dan’s excellent blog with a whole calendar of special “tree-mendous” events throughout the year!
Dan is a novice birder and author of Awbury’s 2022 “Year of Birds” series, 2018 series on Pollinators, “From Wasps to Wind” and 2019’s series on natural fibers. (He is also a former Awbury Arboretum intern.)
The Arboreum’s beautiful grounds are open FREE to the public from dawn to dusk, 365 days a year. Maps available for self-guided tours at the main office, located in the Francis Cope House (Tues – Thurs, 10AM – 4PM or by appointment). Dogs on leash welcome — except not in the garden beds, please. Also available as a unique event venue. Learn more at awbury.org; follow on Facebook and Instagram.