What exactly is a red maple tree?

As spring unfolds, the deep red blooms of red maple trees along the roadsides and in the woods really stand out. Within days, the blooms fall onto the pavement like blood-red snow. Did you know that red maple gets its name from these distinctive blooms?

When someone asks us for a “red maple tree”, it can take a few minutes to narrow down exactly what kind of red maple we’re being asked for, since the term “Red Maple” could apply to several thousand distinctly different cultivars of trees. Like so many plants, red maple is confusing because its “common name” is widely misunderstood.

“Red maples” fall into four basic groups: true red maples, Norway maples with red foliage, upright Japanese maples, and weeping cut-leaf Japanese maples.

True red maples (Acer rubrum) are magnificent shade trees with GREEN foliage that generally grow 40 feet tall and wide, although some get much larger. The species gets its name from its flower color, though many red maples have reddish seeds and red fall foliage as well. There are hundreds of Acer rubrum cultivars, varying quite a bit in shape, growth habit, leaf color, hardiness and other traits. Our favorite is “October Glory”, because it gets spectacular red fall color and keeps its leaves for many weeks after they turn red.

There are other maples with red fall foliage, like the popular “Autumn Blaze”, which are not true red maples. “Autumn Blaze” actually belongs to a hybrid family called Acer freemanii, a man-made cross between red and silver maple, combining the traits of both. These are popular because they have gorgeous fall color (like red maple and sugar maple) but grow twice as fast.

Several cultivars of Norway maples (Acer platanoides) have purple or bronze foliage all season, so they’re often called “red maples”. “Crimson King” is the most popular, however “Royal Red” and “Faasen’s Black” are virtually identical. All have extremely dense, symmetrical crowns, grow very slowly, and are more compact than other maple shade trees. The dense shade and surface roots under Norway maples make it difficult to grow lawns or other plants underneath.

Upright Japanese maples (Acer palmatum) make excellent ornamental trees (not shade trees) and many have red or purple foliage. “Bloodgood” and “Emperor” are two popular varieties, with the deepest red foliage and mature size of 15 to 20 feet tall and wide. Japanese maples do best with some protection from sun and wind. They make excellent accent plants, lending an artistic and aristocratic touch to the landscape.

Dwarf weeping Japanese maples (Acer palmatum dissectum) are extremely popular for foundation plantings and accents. Many have red foliage, including the popular “Crimson Queen”, “Tamukeyama” and “Inaba Shidare”. They tend to stay small (6 to 8 feet tall and wide) but can get much larger.

Professional nurseries list plants using the “Latin binomial system”. Binomial means “two names”. The first name is the “Genus”, or plant family. For maples the genus is always “Acer”. The second name is the “species”, which refers to the particular part of the family tree the plant belongs to. Plant families, like human families, can have hundreds of branches. Then there’s a third name; the “cultivar” name. This could be a catchy brand name, like “Autumn Blaze” (usually created by marketers), or the original name assigned by plant breeders, often the name of the breeder or a family member.

The botanical name of Autumn Blaze red maple is “acer x freemanii “Jeffersred”, after botanist Oliver M. Freeman of the National Arboretum, who bred the first controlled crosses between red maple and silver maple in 1933, and nurseryman Glenn Jeffers, who discovered “Autumn Blaze” in the late 1960s.

Think of the botanical name as a pedigree. The confusion about red maples illustrates why nurserymen prefer to use botanical names when dealing with plants. Only by calling plants by their proper botanical names can we really be sure we’re getting the exact plant with the specific qualities we’re looking for. The use of common names in plant advertising invites misunderstandings and can be an indication of poor quality plants.

Steve Boehme is a landscape designer/installer specializing in landscape “makeovers”. “Let’s Grow” is published weekly; column archives are online at www.goodseedfarm.com. For more information call GoodSeed Farm Landscapes at (937) 587-7021.