The Red Maple (Acer rubrum) is so-named because of its red winter twigs and buds, red spring flowers, red summer petioles (that connect the leaf to the twig), and red fall foliage. Red Maple is a tree located throughout all of Ohio, found naturally in moist areas of open woodlands and more commonly along creeks and bottomlands where the soil is constantly moist to wet. In urban areas, it is abundantly found as a popular shade tree, noted for its brilliant red fall color. Red Maple is native to the entire eastern half of the United States and adjoining southern Canada. Specimens found in the open may grow to 70 feet tall by 40 feet wide, and its soft wood is not nearly as prone to storm damage as is that of Silver Maple. Its branching is upright and generally symmetrical when young, becoming more rounded at maturity and generally without the downswept nature of its lower limbs (like those of Silver Maple). As a member of the Maple Family, it is related to all other species of Maple.
Although Red Maple has been called a cosmopolitan species (meaning that it can be found in many different environments in nature), it strongly prefers deep, moist to wet, acidic, rich soils. This site preference gives it the alternative common name of Swamp Maple. It grows in full sun to partial sun, and is found in zones 3 to 9.
The number one problem associated with Red Maple is its being transplanted into clay soils of alkaline pH, where it often lives under constant stress and becomes stunted. Alkaline soils (also known as high pH soils) result in manganese deficiency, which results in poor iron uptake, which leads to poor nitrogen utilization, which is visualized as chlorotic (yellowing and scorched) leaves and overall stunted growth. Heavy clay soils induce an even greater degree of surface roots than is normal with Red Maple. In addition, weakened trees are more subject to pest and pathogen attack, although Red Maple usually does not have serious problems with borers or Verticillium wilt, its most frequent problems in this area. Leaves of Red Maple are opposite with fairly long petioles, and may occur with a five-lobed character, where the two basal lobes are much smaller, or with a three-lobed, trident-shaped structure, which is more common. In either case, each lobe also has small serrations. The central lobe of Red Maple is wide at its base with shallow sinuses on each side, whereas the terminal lobe of Silver Maple is narrow at its base with deep sinuses. Red Maple, like Silver Maple, has silvery undersides to its leaves, which are easily exposed in the breeze to create a bicolor effect. Red Maple is commonly thought of as having blazing red fall color, but trees found in the wild may display bright yellow, orange-red, or red fall color, or may even have poor green to chartreuse fall color. The red floral buds of Red Maple start to swell by mid-winter, and slowly expand in late winter and early spring to expose the interesting male and female flowers, which are wind-pollinated. The immature red fruits quickly form on long pedicels and sway in the breezes of early spring. By mid-spring, they develop into paired green samaras, which then mature by late spring into brown samaras and fall off. Maple is predominately a monoecious species (male and female flowers on the same tree), but dioecious forms exist (male and female flowers on separate trees), and most of the modern-day cultivars are female trees that have limited fruit set. Red Maple is so-named for its red winter twigs and buds, red spring flowers, and for its tendency to have red summer petioles and red fall foliage. The red twigs of the first year's growth change abruptly to silvery-gray on the second-year wood, which is most evident in winter. The brown-gray bark of maple forms interlacing ridges and furrows with increasing age. The trunk (or trunks) is rarely straight for any length, often having a leaning and twisted appearance and quickly branching into several major limbs.