NVCA Invasive Species Norway Maple Norway Maple Native to Europe, Norway Maple (Acer platanoides) was introduced North America because of its aesthetically pleasing landscaping look. Nowadays varieties of the Norway maple are typically planted in urban areas because of their perceived aesthetics, tolerance to stress and rapid growth.
Why is the Norway maple not a native tree?
It is a non-native popular landscape tree that can spread into native woodlands. Norway maple invades woodlands by out-competing sugar maple due to its shade tolerance. Wildflower diversity is reduced because it forms a dense canopy.
Is Norway maple invasive in Minnesota?
Norway maple is not on any Minnesota control list, but it should be reported when seen in forest areas. The Minnesota Department of Natural Resources provides detailed recommendations for reporting invasive species.
How do Norway maples spread?
Norway maple invades woodlands by out-competing sugar maple due to its shade tolerance. Wildflower diversity is reduced because it forms a dense canopy. Trees are spread by seed. Norway maple are often overlooked and confused with sugar maple.
When did Norway maples come to America?
Norway Maple is said to have first been brought to the United States in 1756, and became even more widespread during the 1940s, when it was used to replace White Elms that were dying of Dutch Elm Disease.
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Why is the Norway maple a problem?
Norway Maples have severe environmental impacts: They grow faster than native maples and other forest trees and its dense, shallow root system makes it difficult for native seedlings to get established. They create a dense shade, under which other species cannot survive, hence my naked garden beds.
Should I remove Norway maple?
A shade tree that could be removed is Norway maple. Its seeds fall onto the forest floor and dominate. Then the slower-maturing, more desirable species listed above can't get a foothold. With that said, if a cultivated Norway maple is planted on your property and is doing well, don't cut it down.
Are Norway maples considered invasive?
Norway maple has been reported to be invasive throughout the northeastern U.S. from Maine to Wisconsin, south to Tennessee and Virginia and also in the Pacific Northwest. Over time, as reforestation occurred across the Northeast, Norway maple joined native tree species as a component of eastern forest ecosystems.
Are Norway maples invasive in Canada?
“Norway maple can be highly invasive with a potentially profound impact on forested habitats throughout southern Ontario and eastern North America. Where it has spread from nearby urban seed sources, many ravines, parks and natural areas exhibit nearly pure stands of this species.
Is Norway maple a good tree to plant?
Norway maples can withstand a variety of environments and tolerate high winds, frost and air pollution, as well as a wide range of soil acidity. They cope well with the typical street tree environment which can include heat, drought, salt spray and poor drainage.
Does grass grow under Norway maple?
The dense canopy and the competition for water and nutrients make it difficult to grow grass under Norway maples. You have several options for improving the landscape. Spread a three inch layer of shredded bark or wood chips under the tree.
Do Norway maples poison soil?
Norway maple has a dense, shallow root system, which releases poisonous chemicals into the soil that kill other plants. Studies have shown that forests dominanted by norway maples have a greatly diminished plant species diversity.
What are Norway maples good for?
The Norway maple is a common tree throughout much of Europe, including (not surprisingly) Norway. It is an important commercial species there just as sugar maple is here in North America. It is used for furniture, flooring and musical instruments. In fact, the Stradivarius violins are said to be made of Norway maple.
Are Norway maples at risk?
It is also capable of invading relatively undisturbed, intact closed-canopy forests, making it a serious threat to woodlands across Ontario. In recent years, awareness of its invasive potential has increased, and many municipalities and some nurseries no longer plant or sell Norway maple or some of its cultivars.
What is Canada's most invasive plant?
phragmites'Canada's most invasive plant,' phragmites, has largely been spread by human activity. Phragmites is a tall, robust invasive grass in our area and it can destroy natural habitats by eliminating vegetation in wetlands, shores, beaches and other natural places.
What maples are not invasive?
Morton Miyabe Maple It is not invasive and would be a good substitute for ash trees where ash borer problems exist. Two excellent selections are 'State Street' and 'Rugged Ridge' varieties.
What eats Norway maple?
Also, as mentioned, its seeds can be eaten by birds and small mammals. In lean acorn years, squirrels and porcupines might also strip away the bark to gnaw on the cambium layer (provided there are no sugar or red maples nearby, both of which provide a tastier and more copious sap).
Are Norway maples at risk?
It is also capable of invading relatively undisturbed, intact closed-canopy forests, making it a serious threat to woodlands across Ontario. In recent years, awareness of its invasive potential has increased, and many municipalities and some nurseries no longer plant or sell Norway maple or some of its cultivars.
Should I remove a maple tree?
You should cut down your maple tree if it is too close to your house, attracting significant pests and insects, has received major storm damage, or it's roots have become invasive. Maple tree roots can span up to 25ft wide, which can cause issues with underground wires and drainage systems.
How do you deal with Norway maple?
Seedlings of Norway maple can be pulled from moist soil before they get too large. Other types of manual removal include digging out saplings and root systems or cutting down large trees. Girdling the trees by removing the bark layer (including the cambium) can also be performed, but is most effective in the spring.
What are Norway maples good for?
The Norway maple is a common tree throughout much of Europe, including (not surprisingly) Norway. It is an important commercial species there just as sugar maple is here in North America. It is used for furniture, flooring and musical instruments. In fact, the Stradivarius violins are said to be made of Norway maple.
What is the best way to control Norway maple?
The best method of controlling Norway maple is preventing the spread of more.
Where is Norway Maple found in our watershed?
Norway maple is a common urban tree in our watershed. Although significant encroachment into natural areas have not been observed to date, there is a high potential that this will occur.
What kind of sap does a sugar maple tree release?
The stems and branches release a white sap when broken. Mature bark have a small crisscrossing groove pattern. Sugar Maple (similar looking native species) The leaf buds are pointed. Leaves are oppositely arranged and have 5 lobes. Sugar maple leaves tend to be longer than wide.
What are some alternatives to Norway Maple?
Good alternatives to Norway Maple include: Hackberry (adapted to a range of soil types and tolerates difficult urban conditions) Sugar maple (needs deep, rich soil) Silver and Freeman maples (needs moist soils) Downy and smooth serviceberry (tolerates wide range of soils and produces edible berries during the summer!)
Why is Norway Maple so popular?
Nowadays varieties of the Norway maple are typically planted in urban areas because of their perceived aesthetics, tolerance to stress and rapid growth.
Does NVCA remove invasive species?
NVCA does not offer a service to remove invasive species on private property. If you are looking for tips on dealing with invasive species on your property, see the links above, or visit Ontario's Invading Species Awareness Program.
Do Norway maples grow in shade?
Norway maples grows rapidly and once established they create a thick canopy which block sunlight from the forest floor restricting growth of native shrubs and ground cover. Also, seedlings can create a thick mat in the shady forest understory and still establish since they are shade-tolerant.
What is it?
The Norway maple (Acer platanoides) is native to Europe. Its natural range stretches from western France in the east to central Russia in the west, and from southern Scandinavia to northern Turkey. It was first introduced to North America in 1756, when John Bartram of Philadelphia imported trees for sale as ornamental landscaping plants.
How does it spread?
Norway maple flowers early in the spring, before many native North American trees and shrubs, which may favor its ability to spread. It grows more quickly than the native sugar maple, and apparently reproduces more quickly as well. It produces large numbers of seeds that are dispersed by the wind.
How can I identify it?
Because Norway maples are so widespread throughout the northeastern US, they are often overlooked as a native species. Additionally, their leaf shape and branching pattern are very similar to native sugar and red maples.
How can I control it?
Seedlings can be pulled by hand and small to large trees can be cut to the ground. Repeat when necessary to control re-growth from sprouts.
Image Gallery: Norway Maple
Norway maple leaves and samaras. Contrast with sugar maple leaf and samara in the next slide. Photo courtesy Norm Meyn, blogs.pjstar.com
What is the color of maple sap?
Unlike sugar maples, its sap is milky, evident when petioles or leaf veins are cut (unless it’s very dry). The small, pale yellow or yellow-green flowers are held in corymbs at the end of branches in spring. They can be rather showy when the whole tree is in flower. Its 2-inch wide winged seed capsules (samaras) are light green until the fall when they turn yellow and then brown.
How many lobes does a maple tree have?
The palmately lobed leaves (arranged oppositely) are usually 4-7 inches wide, wider than those of sugar maple. The leaves usually have five lobes. It leafs out earlier, and the leaves remain green longer than other maples. The fall color varies from yellow-green to yellow or tan. It doesn’t turn red or orange like other maples.
Where did Norway maples come from?
Norway maple (Acer platanoides) was introduced as a shade tree in Philadelphia by John Bartram, a botanist and horticulturist who got the seeds from London in 1756.
When do samaras mature?
The seeds are held in clusters at the ends of branches. Each individual samara is 2-4 inches long. The fruits mature in September or October and can remain on the tree into winter.
Can cultivars escape cultivation?
There are now many cultivars available but even some of those can escape cultivation. The gardener concerned with biodiversity should look elsewhere.
Is the sage tree invasive in Connecticut?
Most people probably don’t even realize it’s considered invasive in Connecticut. The tree is on our state’s official list of invasive plants but is not specifically banned. This is presumably because there are cultivars that are less aggressive or haven’t been evaluated.
How to control Norway maple?
Physical control: Seedlings are easily hand-pulled from moist soil; larger saplings can be dug or pulled using equipment. Cutting or mowing may be effective. Although Norway maple can resprout from cut stumps, it seems to do so less aggressively than many invasive trees and shrubs. The incidence of regrowth also seems to depend on age, with mature trees regrowing less readily after felling than seedlings and saplings (Munger 2003). Mature trees can also be girdled in early summer by removing a four inch strip of bark and cambium from the whole circumference of the trunk. All cut and girdled trees should be monitored for regrowth and treated with herbicide if needed.
What is the WIGL?
The Woody Invasives of the Great Lakes (WIGL) Collaborative brings interested partners together to consolidate information on woody invasive plant species. The WIGL Collaborative is coordinated by the Midwest Invasive Plant Network.
How is Norway maple distributed?
Norway maple seed is distributed by wind. Research has shown that the normal maximum range of Norway maple seed travel is 165 feet from the parent (Matlack 1987). This is a relatively low dispersal distance compared to species whose seeds are bird or wildlife dispersed. Through movement of seed from successive generations, Norway maple can eventually invade interior areas.
What is Norway maple?
Look-alikes: Of the native maples, Norway maple is most similar in appearance to sugar maple (A. saccharum). Norway maple can be distinguished from sugar maple by the milky white sap that appears at the base of leaf stems when leaves are pulled from twigs. Native maple species have clear sap. The samaras of Norway maple are somewhat larger ...
Which maple species have clear sap?
Native maple species have clear sap. The samaras of Norway maple are somewhat larger than those of native species, and the angle between the two halves is wider.
Where is Norway Maple most prevalent?
It is most prevalent at disturbed sites such as abandoned residential, commercial and agricultural land, and highly fragmented and otherwise disturbed forests. However, studies have shown that Norway maple seedlings can establish and dominate in high-quality forest interiors (Webster et al. 2005).
Do Norway maples produce less seed?
Research conducted at Penn State University indicates that certain Norway maple cultivars produce significantly less seed than the species and other seedy cultivars (Conklin and Sellmer 2009). Some limitations of the study are that only six cultivars were evaluated (of over 20 cultivars readily in trade), and that the observation period was three years, which is relatively short compared to the total reproductive life of a tree. Population modeling indicates that for long-lived species, such as trees and shrubs, even relatively low seed producing types can contribute to invasive populations (Knight et al. 2011).
