Norway maple

Botanical name

Acer platanoides

Type

Deciduous shade tree from Europe; green and purple-leaved forms

Size

40 to 98 feet tall with a wide, rounded crown (USDA Forest Service)

Hardiness

Zones 3 to 8 (Utah State University); zones 6b to 7b here

Where it is found

Older planted lots on the valley floors, about 4,000 to 5,100 feet

Known weak points

Leaf scorch in hot dry sites, dieback after pruning, aphid honeydew

A Norway maple casts dense shade. People often know it by its dark red-leaved cultivars such as 'Crimson King'. This page is about identifying it, the elevation bands where it lives, the problems we see described for it in Intermountain landscapes, and when pruning or removal is the right call.

How do you identify a Norway maple?

The leaf is the clue. It is opposite on the twig, usually five-lobed, with a wide base, and when you pull a leaf from its stalk a drop of milky sap appears. Utah State University notes the sap may fade late in summer, so check in spring or early summer. Fall color is yellow to orange.

The fruit is a pair of winged seeds set nearly flat, 1.4 to 2.2 inches long according to the USDA Forest Service. Bark on old trees is furrowed. Sugar maple has watery sap and a different leaf shape; the milky stalk is what separates the Norway.

• Five-lobed opposite leaves with milky sap in the stalk
• Paired seeds spread nearly in a straight line
• Dense, round crown that shades heavily
• Furrowed bark on older trees

Where does it grow in Reno, Carson City and the Carson Valley?

It is a planted tree of the valley floors. Reno's ZIP 89501 is zone 7b, Carson City's 89701 is 7a and Minden's 89423 is 6b, and Utah State rates it high for alkaline soil tolerance and for salt, which suits our ground. Reno is near 4,505 feet and Carson City near 4,680 feet.

Above that, on the Nevada side of Tahoe at 6,200 to 7,100 feet, you will find far fewer; the lot trees there are conifers. The Forest Service reports it growing outside cultivation in Washington, Idaho and western Montana, not as a wild tree of our basin.

What goes wrong with it here?

Utah State University calls it a medium-quality tree that is over-planted in most of Utah, with leaves that scorch on very hot, dry sites and a fairly common dieback of trunk or branches after pruning. That dieback is why a heavy cut on a Norway maple deserves caution. See drought stress and dieback for how an arborist tells scorch from real decline.

Aphids can leave a sticky honeydew on cars and patios in some years, though USU says they rarely harm the tree. The crown is heavy, so a split fork or a limb on a roof is the structural worry; see storm and snow-load breakage. Like other large maples, it is rated not good under power lines.

Pruning, cabling or removal: which is the right call?

Dead wood and hazard limbs come off any time. For everything else, late winter is the usual window. Because dieback after pruning is reported, an arborist favors a few well-chosen cuts over a large number of cuts at once. See crown thinning, raising and reduction.

Cabling and bracing can help a sound tree with a strong main trunk and one weak union. Removal is usual when the trunk or roots are decayed, when the crown has lost most of its live wood, or when a split union overhangs a house. Big Norway maples often need a large tree removal crew and, in tight yards, a crane.

What does Battle Born Tree Service do about a Norway maple?

Call 775.232.8243 or use the estimate form on this page. An ISA Certified Arborist looks at the tree on site, explains what is wrong and tells you whether the job is pruning, cabling or removal. Credential WE-11728A is held by one of our two certified arborists. For firewood, call the office for availability and pricing.