Fall 2012 color outlook for landscape plants and trees

The 2012 season will be earlier and possibly shorter, due to severe summer.

As the days begin to get shorter and football season starts, fall color is always a topic of interest in Michigan. Predicting how intense our fall color will be is an inexact science at best. We know that fall color is a result of the breakdown of green pigments (chlorophyll) that reveals pigments that already present or are accumulated in leaves such as carotenoids and anthocyanins. In Michigan, maples, oaks and sassafras are among some of the trees that provide our most consistent fall color.

The general rule is that clear days and cool nights provide the optimal scenario for brilliant fall color. This year’s severe summer weather throws another factor in this mix, however. In many parts of the state, we have seen leaves begin to turn color early in response to drought stress (Photos 1 and 2). As noted in a related article, we are also seeing considerable early leaf drop in areas where trees have been especially hard hit by drought (Photo 3). This suggests that the color show in Michigan could be shorter than usual.

Photo 1. Sumac in late July. Taken in Dewitt, Mich.

Photo 2. Sassafras in late August. Taken on MSU campus.

Leaf shed
Photo 3. Early leaf shed.

It’s still possible that this set-up could change if trees get some relief from the current levels of drought stress and we get into a cooler and wetter pattern in the next few weeks. This would reduce tree stress, enabling trees to hang on to their leaves and gives us a longer show.

Dr. Cregg’s work is funded in part by MSU’s AgBioResearch.

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