Eastern Red Maple

Growing Conditions

As previously stated, this tree will grow almost anywhere in our area. While it prefers soil on the wetter and more acidic side, it really can adapt to where it is placed. It does grow faster in full sun, but can also succeed in part shade.

Identification

While one of the easiest tree’s to identify in our area, it is also maddeningly difficult to pinpoint exact characteristics due to their high genetic variability. However, there are some obvious things to look out for.

The Bark is very different from tree to tree, but in general is either smooth when young, or furrowed into long vertical cracks when older. One common (but not ubiquitous) feature is a slightly red inner bark that is visible as the cracks expand. Due to the myriad bark variations on Red Maples, it takes a lot of experience observing enough maple bark variations to feel somewhat confident in identifying a red maple from just the bark. Even then, there are some variations of bark between Red, Silver, and sometimes Sugar Maple that can look similar. For Red Maples, the bark is probably the least useful identification characteristic. In any case, always use multiple identification items or as many as possible.

Buds are usually red to green, round, and in clusters. Usually scale edges bright and clearly defined (actually hairs if you look closely). Buds are opposite, just like the leaves. During the winter, this can be fairly obvious on leafless branches and twigs. The only buds that look similar to Red Maple are those of Silver Maple, so always use the twig & bark during the winter as a second point of reference.

Twigs show thin lead scars that span just less than half way around the twig. Vascular bundle circles are visible, usually corresponding with the number of lobes (3-5). Breaking open a twig has no smell, while a twig of the closely related Silver Maple has a very unpleasant odor.

Leaves are opposite, and highly variable, but usually with 3 main lobes. Sometimes the lower 2 lobes near the stalk are just prominent enough to count 5, and sometimes the leaf base can be either cordate (heart shaped) or round (like a bowl). The middle lobe is sometimes close in length to the 2 side lobes, or sometimes much much longer. The leaves are always serrated, with sharp V-shaped notches in between each lobe. (if you see a leaf that looks like a red maple, but is smooth and with U-shaped notches, it is probably a Sugar Maple).

The winged Fruit, call Samaras, appear BEFORE the leaves in the spring (also like Silver Maples). The samaras are usually red, and drop along with leaf emergence. They sprout in early summer of the same year, and do not store well.

Checkout the Key to Acer at the Flora of Southeastern United States, for a detailed guide.

Flowering & Reproduction

Here in northern Delaware, this is one of the first trees to break dormancy in the early spring. By the first week of March, the red flowers are starting to open, giving way to winged seeds by the end of March. These seeds start dropping as new leaves bud out in early April.

The flowers are very interesting. Acer rubrum as a species has polygamo-dioecious flowers that are structurally perfect. I don’t mean perfect as in without-defect, I mean that the flowers can structurally contain both female and male parts within the same flower structure. However, sometimes only the stamens (male) are present, sometimes only the pistil (female) is present, and sometimes both are present (bi-sexual) like a standard perfect flower. Some trees are all male (Staminate flowers) and so produce no seed, while some are all female (Pistillate flowers), and still others have both or even all three. On trees that have both male (Staminate Flowers) and female (Pistillate Flowers), entire branches might one type, while adjacent branches are another. (1)(3)

Red Maples produce seed fairly consistently every year. They produce heavy and fast, usually inundating the surrounding areas with seed that looks like snow as thousands of these small helicopters gracefully fall to the ground during a spring breeze.

Propagation

Seed Propagation

Each helicopter (samara) falls as ready-to-go seed. They require no stratification or scarification, and will germinate in early summer to establish before the end of the year. Even a young 1-FT diameter tree can drop over a million seeds within a 2 week window. Germination rates are usually around 85-91%, with about 17grams for 100 samaras (1). These seeds are extremely easy to grow from seed by just broadcasting over a growing bed and lightly covering, no need to remove the wings.

Vegetative Propagation

Red maples grow back well from stump sprouts and hidden dormant buds at the base of most branches (good for coppicing). However, it is difficult to propagate through cuttings. Cultivars of Red Maple, such as the famous “Autumn Blaze” are propagated through grafting onto wild root-stock.

Root Structure

One of the reasons why Red Maples are so adaptable is their rooting habit. They have shallow roots, typically only within the top 10 inches of soil. Even the initial tap root will quickly stop growing down after only a few inches and turn sideways (1). The shallow roots run wide and far in all directions, coming up close to the surface is fibrous webs. Any kind of raised garden bed or other fertile area of soil within the canopy of this tree will often be quickly colonized by these advantageous roots. Due to this habit, Red Maples also response amazingly quickly to any kind of organic fertilizing materials in the area.

Ecology

My family and I setup a small kiddy pool under the shade of our largest Red Maple a few years ago. It was a constant battle to keep it clean, as overnight, it would appear to have rained thousands of small bead sized lumpy balls from the sky. It was a pain for pool maintenance, but an awesome clear-as-day indication of the life and ecosystem in our tree.

This tree is an important source of winter food for deer, squirrels, and birds. Red Maples also host several insect species, such as: Inchworms, Rosy Maple Moth, Oval-based Prominent, Retarded Dagger Moth Orange-humped Maple Worm, Maple Lopopers, Baltimroe Bomolocha, Cecropia Moth, and many others! (2)

Also, because this tree flowers so early in the spring, it provides some much needed early pollen to many pollinators hungry for food early in the season.

DNREC rates the Red Maple as the most ecologically important tree in Delaware, sharing the top spot with Wild Black Cherry. It supports populations of songbirds, game-birds and waterfoul, bees, butterflies and moths, and small mammals. (9)

Home Landscaping

I’m not sure that anyone wouldn’t want a Red Maple! While their beautiful red foliage is the most common, there are also trees with yellow and orange coloring to be found in the fall. Some even have all 3 colors on the same tree!

While seed drop is heavy in the early spring, they are light and taken far by wind. Seeds decompose quickly in a home landscape and rarely become an issue. Leaf color in the fall is one of best around.

The due tend to create very dense shade however. This is great when one wants a traditional shade tree, but this can also means that the light available under these trees is very low. Great for grasses and maybe even ferns, but gardens and other trees will have a hard time out competing the dependable Red Maple.

History & Traditional Use

Although most think that only Sugar Maples can be tapped for Maple Syrup, this is not true. Red Maples can also be tapped for syrup, but more sap will be needed to create an equivalent amount of syrup as sugar content is a bit lower. Native Americans were known to make syrup using the freeze/concentration method, which is the same method used in the us during prohibition to get a nice alcoholic hard apple cider without any distillation. During this process, the syrup was allowed to freeze partially outside. The water would freeze solid and be removed, leaving the more concentrated sugar-water behind.

Early pioneers used the bark to make cinnamon-brown inks and dyes.

Many Native American nations used Red Maples as drugs, food, fiber, dye, and decorations. Drugs were mostly from the inner bark. Examples include the following: (10)

Cherokee - Bark infusions and preparations for analgesic for cramps, anti-diarrheal for dysentery, wash for sore eyes, gynecological aid for menstrual cramps, measles treatment. Fiber from bark used to make baskets. Wood for lumber, furniture, and crafts of carved wood.

Ojibwa - Eye wash prepared with inner bark. The red maple leaf was one of the sacred plants to the Ojibwa, and was present in many of their decorations and medicine lodge.

Iroquois - Medicine for blood purification, eye wash and cataract treatment, compound with other ingredients for wash for hunting traps. Processed the bark into a powder to make bread. Wood to make bowls.

Micmac - Used bark fiber for baskets

Malecite - Made basket splints with bark fiber.

Potawatomi - Inner bark used for eye wash, hunting trap deodorizer wash

Seminole - Bark preparation used for sores, orthopedic pain, and hemorrhoids. Wood used to make spoons, arrowheads, and ox yokes.

Abnaki - Used sap as sweetener and sugar.

Algonquin of the Quebec region- Used sap to make sweetener and sugar

Credits and further reading on the Red Maple!

1. US Forest Service (https://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_2/acer/rubrum.htm)

2. Lady Bird Johnson (https://www.wildflower.org/plants/result.php?id_plant=acru)

3. Harvard Arboretum (https://arboretum.harvard.edu/stories/red-and-silver-maples-and-their-hybrid-in-flower-now/)

4. Key to Acer, FSUS (https://fsus.ncbg.unc.edu/main.php?pg=show-key.php&taxonid=63913)

5. Plant Portrait - (https://www.youtube.com/watch?v=VxySD8tyiKs)

6. Tree of the Week - U.Kentucky - (https://www.youtube.com/watch?v=6aTZlc65Dj8)

7. Forests for the Bay - (https://www.youtube.com/watch?v=nebR2BEjmB4) (I hate how foresters talk about this tree because it is not important to the lumber industry, but this is a fantastic channel otherwise)

8. bPlant page (https://bplant.org/plant/91)

9. DNREC Native Indigenous Trees of Delaware (https://documents.dnrec.delaware.gov/fw/conservation/Native-Indigenous-Trees-of-Delaware.pdf)

10. Native American Ethnobotany, Daniel E. Moerman, Timber Press 1998, pg. 40. ISBN 978-0-88192-453-4 (https://www.amazon.com/Native-American-Ethnobotany-Daniel-Moerman/dp/0881924539)

.