10/19/11 'AUTUMN BLAZE' HYBRID MAPLE

'AUTUMN  BLAZE' HYBRID MAPLE , SPRUCE AND BIRCH TREES

'AUTUMN BLAZE' MAPLES PLANTED TEN YEARS AGO

EVEN LEAF PETIOLES AND TWIGS ARE RED

...LEAF VERY SIMILAR TO SILVER MAPLE

Wednesday, 8:00 AM.  38 degrees, wind W, light with occasional moderate gusts.  The sky is overcast but looks like it might be clearing, and the barometer is trending up.  It rained a bit last night and the decks are wet.
    Although fall color is certainly winding down here, there are still some very brilliant contenders for our visual attention, and the hybrids between silver maple, Acer saccharinum, and the red maple, Acer rubrum, are very evident.  Although these hybrids also occur in nature,  those we see are nursery propagated. There are a number of named varieties, the one I am most familiar with is ‘Autumn Blaze.’  I planted two of them as perhaps 6’ whips ten years ago, and they are  over 20’ tall now and  6.5” DBH (diameter at breast height). A very apparent virtue of these hybrid trees is fast growth, and both parent species contribute to that characteristic.  The leaf shape of the ‘Autumn Blaze’ is very much like that of the silver maple but the sinuses between the leaf lobes are not as deep.  The leaf petioles and the young branches are a colorful deep red.
    Fast growth in trees is usually a mixed blessing or even a curse.  But whereas the silver maple in particular is weak wooded and prone to many problems, the hybrid seems much stronger in every way.  But the outstanding characteristic is its  absolutely brilliant, and in my experience unfailing, scarlet red fall color.  Consequently these trees are very popular and a great number have been and are being sold. 
    There are hazards in all of this popularity.  When trees truly become a fad, too many appear in the landscape and we tire of them, and if too many of any type of tree are planted it decreases the diversity of the urban forest.  We have seen his happen with the American elm, with varieties of ash and  honey locust trees, even with flowering crabapple trees.  Lack of diversity leads to insect and disease vulnerability and the threat of epidemics. Personally, I now recommend these hybrids as accent trees rather than as the backbone of a landscape.  And I am deemphasizing their use as street trees.