Guide

Look closerPlants

Norway maples: the street maple that keeps its leaves late

November

Norway maples, a European tree planted widely along Massachusetts streets, often hold their leaves longer than native maples, then turn yellow. Holding leaves longer has been proposed as one way this invasive tree outcompetes natives for light.

Why this time of year

Once most native maples have dropped their leaves, a maple still holding a full crown stands out.

How to notice it

  1. Scan street trees and yard-edge maples for ones still holding leaves while nearby maples have gone bare.
  2. Check the leaf: broad, four to seven inches across, with five to seven pointed lobes.
  3. Snap a leaf's petiole fresh off the twig; a bead of milky white sap means Norway maple (it shows best earlier in the season).
  4. Look at the color: its leaves turn yellow, often hanging on past native maples.

Try this with kids: Can you find a maple on your street still holding its leaves when the maples next to it are bare? Snap a fresh leaf stem and see if white milky sap comes out.

petiole: the thin stalk that attaches a leaf to a twig

Sources

  • sudbury.ma.usMDAR Massachusetts Prohibited Plant List (2023, mirrored by the Sudbury Conservation Commission): lists Acer platanoides, Norway maple.
  • orleansma.govMIPAG list (town mirror): Acer platanoides voted INVASIVE; out-competes native vegetation, including sugar maple.
  • massaudubon.orgMass Audubon: Norway maple is invasive in Massachusetts and, unlike the sugar maple, has milky sap.
  • massaudubon.orgMass Audubon: native fall-color timeline, red maple earliest (mid-to-late September on), oaks and aspens mid-to-late October. Does not mention Norway maple.
  • extension.uconn.eduUConn Extension: Norway maple leaves often persist longer than those of native maples; petioles exude a white sap when broken, which distinguishes it from native maples.
  • extension.umd.eduUMD Extension: white milky sap exudes when a leaf petiole is detached; Norway maple is invasive.
  • naturalresources.extension.iastate.eduIowa State Extension: Norway maple holds its foliage about two weeks longer than native North American maples in autumn; milky sap when a petiole is broken.
  • newporttreeconservancy.orgNewport Tree Conservancy (Rhode Island): Norway maple leafs out almost two weeks earlier than native red and sugar maples and retains its leaves longer.

Checked against these sources on September 28, 2026.

In the guide for November

Also worth noticing