Norway maple is a deciduous tree that grows 40-60 ft. (12.2-18.3 m) tall. The opposite leaves are palmately lobed with 5-7 lobes. The margins are marked with a few large teeth. Flowering occurs in the early spring before the leaves emerge. The flowers are inconspicuous and develop into large double samaras that mature in the late summer. Norway maple is very similar to sugar maple but can be distinguished by the fruit, sap and bark. The angle of seed wings of Norway maple is approximately 180 degrees, while the angle between the seed wings of sugar maple is near 120 degrees. Broken leaf petioles of Norway maple ooze white sap while the sap of sugar maple is clear. Norway maple bark is regularly grooved, and sugar maple bark has irregular plates. Norway maple has invaded forested ecosystems throughout the northeastern United States and parts of the Pacific Northwest. Once established into a forest, it has the ability to shade out the native understory and out-compete the native tree species. Norway maple is native to Europe and was first introduced into the United States in 1756. It has been, and continues to be, widely sold as an ornamental. (Source: EDDMapS)
Management Options:
A. Hand Pulling
Control can often be accomplished by hand-pulling for small populations (less than 1/4 acre). Plants pulled early in the season are much smaller and easier to manage.
B. Cutting & Mowing
Mowing (or brush hogging where woody plants are present) is suited to non-rocky, open areas that are not too steep for the equipment. Obviously, mowing affects all plants mowed, not just the target species. Equipment should be cleaned prior to being brought to the site and should be thoroughly cleaned of all seeds and plant parts before leaving the site.
C. Propane Torch
Backpack-mounted propane torches can be used for invasive plant control. This method uses targeted fire to heat the base of a plant, killing it. Some plants with developed roots may resprout after this treatment. Safety training is needed before using this method.
D. Herbicides
Herbicides are pesticides used for vegetation management. Herbicides can be a valuable tool in controlling invasive species, but they must be used with caution.
Always read the entire herbicide label and apply herbicides according to label directions. Wear the personal protective equipment specified on the product label and heed any and all environmental restrictions stated on the label.
Most herbicide products, especially those marketed to homeowners and small property owners, are classified as “General Use” pesticides. Only licensed pesticide applicators are allowed to purchase or apply “Restricted Use” pesticides.
E. Grazing
Grazing means using animals to eat plants.