Maple trees in the northern U.S. are coming into bloom at this time of year. Maples bloom in late winter and early spring, and the flowers come in green, yellow, orange, and red hues. There are about 130 species worldwide, and except for one species, all are found in the northern hemisphere across Asia, Europe, Africa, and North America. Thirteen maple trees are native to North America, and we will take a look at a few of the more common ones.
Several species are large trees, reaching from 40′ to 65′ in height with 20″ to 60″ diameter trunks. Trunks are dark grayish-brown with ridged bark. Crowns appear generally rounded and root systems are widely spread. Maple trees do well in most habitats, particularly moist to wet soil, along streams or in bottomlands.
Sugar maple, Acer saccharum, is well known for its maple syrup, marketed world-wide. When temperatures drop below 40˚, maple trees stop growing and excess starch is stored until temperatures start to rise again. Enzymes in the tree change the starch into sugar which is carried by tree sap flowing through the xylem and phloem cells, located just beneath the bark. A tap gently pounded through the bark intercepts some of the sap and collects it into buckets. It takes 40 gallons of sap to produce one gallon of maple syrup. Historically, the wood was used for railroad rails, plow blades, and wagon wheels. After burning, its ashes are rich in potash and make excellent fertilizer as well as an additive for soap and pottery glazing.
Black maple, Acer nigrum, is a close relative to the sugar maple, and these two species easily hybridize. Both species are shade tolerant, often found growing together for several years as understory trees. Sap from black maple trees may also be used in maple syrup production. Black and sugar maples are hardwoods, stronger and harder than other maple species, and valued for use as basketball court and bowling alley floors, workbenches, cutting boards, and baseball bats.
Bowling alley by vtwinpixel, Getty Images; Maple & other baseball bats by Comstock Images: Maple workbenches from thelinke, Getty Images Signature
Red maple, Acer rubrum, provides food from seeds, buds, and flowers for squirrels, chipmunks, deer, moose, and elk. In winter, stumps and small twigs are an important food source for rabbits. Pollen is produced early in the spring and is a much needed food source at this time of year for bees and other pollinators. Red maple is also attractive to insects and fungi, which invade the wood and create many open cavities in trunks and large branches, favored as nesting sites for wood ducks and other species.
Red maple has several qualities that have made it a widely used ornamental tree. It grows well in shady sites; it is tolerant of flooding and water-logged soils; it is one of the first to colonize disturbed sites and anchor the soil, and it has a rapid growth rate, colorful flowers and foliage, and lives 75 to 100 years. Maple flavored drinks, such as tea, are made from inner bark scrapings. Bark is also used in the production of ink and black or brown dyes. The wood is used for smoking meat and in the production of some whisky varieties.
Silver maple, Acer saccharinum, is a fast growing tree with a root system attracted to any source of water. It is easily grown in shady areas and wet soils, make it a well-liked ornamental tree. However, it causes many sewer and drain issues in urban settings in its search for water. The wood is hard but very brittle, and branches easily break in heavy winds. This often results in trunks having hollow cavities used for shelter by various animal species including wood ducks and squirrels. Seeds are abundant and are a favorite for birds and small mammals. The sap makes a delicious syrup, but requires twice as much volume as sugar maple trees, making it not commercially viable.
Box elder, Acer negundo, is another maple species that is often found near water. This tree easily tolerates drought and extreme cold, although the wood is weak compared to other maple species, and branches often break when subjected to heavy loads of snow and ice. Box elder produces abundant seeds late in the year that provide a great winter food source for mice, squirrels, and seed-eating birds. Branches are small in diameter, so it is not often used for lumber, but it has several uses as pulp wood for producing crates, boxes, and composite wood panels.
As you are out walking in your area, be sure to look for the many species of maple trees that grow in yards and woodlands, often distinguished by bright flowers, abundant seeds, and lively green foliage. Also, be sure to take the chance to observe their spectacular fall foliage later in the year.
