We decided it would be a good idea to thin out the trees in our wooded lot, to allow more sunlight in to support the growth of understory fruit trees and berry bushes. Arborist Matthew “Twig” Largess came to look over the situation and make some recommendations. Matt pointed out a number of Norway Maple trees. He explained that they were invasive and removing them should be a priority.
Non-native Norway Maples can be easily mistaken for native Sugar Maples. Imported from England in the early 1700’s to use as a shade tree, Norway maple is a popular urban tree. Unfortunately, Norway trees are harmful to the environment. They grow faster than native maples and displace them. Norway Maple canopies are more dense. They leaf out earlier in the spring and drop foliage later in the fall. Native species are unable to survive under the Norway maple’s dense shade.
In addition, Norway Maple leaves contain a toxic latex that harms insects and pollinators. They also have dense, shallow root systems, which release poisonous chemicals into the soil. This makes it difficult for native seedlings to take root and thrive.
So how does one tell the difference between the two types of maple tree?
- Norway maple leaves have more lobes, typically 5-7, compared with the sugar maple’s 3-5.
- The front 3 lobes of the Norway Maple leaves are often wider at the base, and the front three lobes of the Sugar Maple often widen toward the tip.
- Norway Maple leaves are a darker green.
The leaf differences are subtle, so the best way to identify the tree is to remove a leaf, stalk and all, from its stem. Norway Maple leaf stalks exude a milky white sap if cut or plucked.
- Norway Maple flowers appear in rounded upright clusters. Sugar Maple flowers droop down.
- Norway Maple’s winged pair of seeds, samaras, spread more horizontally when hanging, and the seed flat. The Sugar Maple’s samaras are downward-oriented when hanging, and the seed is round rather than flat.
- Sugar Maples are more colorful in the autumn than Norway Maples.
I took a walk around to neighborhood in search of a Sugar Maple and saw not a one. I did, however, see dozens of Norway Maple trees. I finally found a Sugar Maple at nearby Goddard State Park.
Sugar Maple is tapped for maple syrup, making it a likely candidate for a food forest. Furthermore, the plump seeds of the Sugar Maple samaras are edible. Seeds harvested during spring will be sweeter than those harvested later. If the seeds are bitter in their raw form, they can be roasted with a coating of oil or boiled in water (~15 min) to dissipate the bitterness.
Once the Norway Maples are removed, I’m thinking it would be nice to plant some Sugar Maples at the roadside edge of the wooded lot. I checked the Arbor Day website, and, as a member, I can order 3-4′ saplings for $15.99 each. Sounds like a plan.