When people are shopping for a shade tree, they almost always ask me what I think of Autumn Blase Maples. My first thought is always, WOW, another one.....those must have been marketed like crazy at some point! Truth be told, it would be one of the last trees I would plant in my yard.
First, a little science and a little history. Silver maple (Acer saccharinum) and red maple (Acer rubrum) flower at the same time and can cross pollinate. The resulting tree is a naturally occurring hybrid referred to as freeman maple (Acer x freemanii). Before I get into the specifics of the Autumn Blaze Freeman Maple, it will help to understands it's heritage.
First the Silver Maple
Fast growing.
They are often referred to as a soft maple because they damage easily in wind storms.
Yellow fall color.
Easily grown in urban soils.
Tolerant of higher alkaline levels.
Toleralnt of lower oxygen levels.
Native to Wisconsin.
Red Maples
Red maples are slower growing.
Troubles with low oxygen levels and higher PH of urban soils. Soil PH above 6.5 will cause the leaves to become lighter in color.
Less damage in wind storms.
Red fall color.
Native to Wisconsin.
Autumn Blaze Freeman Maple was the first freeman maple marketed which is one reason I believe it is so well known.
It was believed to have the fast growing attributes of the silver maple but the stronger wood of the red maple.
Will tolerate urban soils.
Tolerates the alkaline soils of urban areas and of Southern Wisconsin.
Tolerates low oxygen levels of urban soils and soils from recent construction.
Red Fall Color
The problem is Autumn Blaze Maples do suffer from storm damage easily. With the silver maple and the autumn blaze maple, this is not necessarily from weak wood but from acute branching angles that cause bark inclusion. When bark becomes included, there is less wood in the connection between the branch and main stem causing a weakness (See the image below). The branch on the left is closer to 90 degrees and is strong. The branch angle on the right is narrow (acute), resulting in the bark becoming included resulting in a weak branch. Proper pruning when the trees are young can limit this problem, but it will not eliminate it.
There are very good freeman maple alternatives. The varieties Autumn Fantasy and Sienna Glenn have the same fast growing attributes of the silver maple, but better branching habits and the fall color of the red maple. They are both tolerant of urban soils.
Ultimately, autumn blaze maple is popular and well known. Many of my customers inquire about them. It does grow fast and has a nice, red fall coloring, but the narrow (acute) branching habit makes the variety prone to storm damage. Varieties such as autumn fantasy or sienna glen have the same desirable attributes, but have better form and therefore incur less storm damage.
