Feature Tree – September 2005
Red Maple
(click here for Tree of the Month archives)

Common Name: Red Maple
Scientific Name: Acer rubrum
Family: Aceraceae

This Tree in Colorado: Best in neutral or acidic soils; likely to develop iron and manganese chlorosis over time in alkaline soils. Hybrids with silver maple such as ‘Autumn Blaze’ have performed well along the Front Range.

Growth Habit: Various, depending on cultivar

Growth Rate and Mature Size: Medium growth rate; size varies with cultivar; most should reach about
35 feet tall.

Hardiness: Depends on cultivar; some hardy to Zone 3; 7500’ or lower.

Cultivars: ‘Red Sunset’ is widely sold. ‘October Glory’, ‘Northwood’, ‘Autumn Flame’ and ‘Autumn Spire’ are also available, along with several cultivars of red-silver maple hybrids.

Leaves: Opposite, simple, 2-4” long and wide, 3-5 lobes. Upper surface green, lower surface gray-green. Fall color varies, yellow to orange-red to red. Best fall color in acidic to neutral soil pH.

Flowers: Small, reddish-purple, prior to leafing.

Fruit: Twin samara, often reddish

Landscape Value: Medium-high for shade and fall color; lowered value for trees that become chlorotic.

Potential Diseases and Insects: chlorosis due to less available iron and manganese in alkaline soils

Best Advice: May look good for several years before developing chlorosis. Test soil pH before planting; ideally 7.4 or lower. Likely more successful in older, longer-cultivated soils than in new housing areas. Best in large rooting areas such as tree lawns; not drought-tolerant; avoid planting in heat-loaded sites.

Information Source: Dirr, MA, Manual of Woody Landscape Plants, 5th Ed.

Photos: Robert Cox