Norway Maple

Norway maple is a deciduous tree that typically grows 40- to 60-feet tall. It was imported for landscaping in urban and suburban areas as a shade tree. Varieties with red and purple leaves are common. It is easy to spot this species in the fall because its leaves remain intact longer than any of our native maples. It can also be distinguished from other maples because the leaves and twigs ooze milky sap when cut or torn. 

Norway maples produce large numbers of winged seeds that establish quickly and develop dense stands that outcompete native plants. This species is hardier than many native tree species, and its ability to grow in deep shade makes it particularly threatening to native forest habitats. 

To eliminate the seed source, it is important to remove mature Norway maple trees. Hand pulling of seedlings and other mechanical removal, such as removal of saplings using a Weed Wrench, may be effective for small populations. Girdling (removing tissue around the circumference) can be effective for mature trees. Glyphosate-based herbicides or triclopyr based herbicides are effective when applied to cut stems or girdles. Norway maple stumps sprout vigorously when cut unless herbicide is applied to the freshly cut stump. Always read and follow the directions on the label when using herbicide.

In Newburyport’s yard waste center, any cuttings should be contained in a brown paper leaf bag with a closed top and placed in the designated location per the attendant or cuttings may disperse and reestablish. You may also call the Sustainability Office at 978/499-0413 to get advice on the best disposal options for invasive plant cuttings.