Friday, September 24, 2010

Fall colors on Trees

Here in Montgomery County and everywhere in Southeast Texas, we begin a little bit later than in the north to see fall colors. Sometimes, we see almost nothing at all except for the Chinese Tallow which is considered an invasive species and outlawed from trees nursery sale inventories. That tree is very ornamental in the fall, one trait that brought its popularity in the past century. In reality, this is not a place for a fall showing of trees, but sometimes it really surprises me what the native trees will do. Technically the Fall season has arrived, but it will be a while before the trees think it has arrived due to our southern position.

What causes the differences we see each year? It is the weather, pure and simple. Rain while the leaves become deprived of nutrients is a key component in determining the colors. The sugar content of a leaf is very important to its coloration and brilliance. If we get an early frost, the leaves are more likely to drop as ugly dried brown leaves than colored leaves, although it depends on the species and the moisture as well. Because we have had a near average rainfall this year, I am expecting a better fall show in this area. We have a fairly large population of native hardwoods interlaced among the evergreens, enough to give us a spectacular show when the conditions are right. I have seen a few trees already beginning to have fall colors, even though it is very hot. Too much heat can offset the beauty  given by the water. If we do not receive much rain and the heat stays with us, fall will again just be a blink of the eye. We need long and cool night with some light rain. More details can be found in this link: Explanation of Fall coloring

USDA Forest Service reports the fall colors for all national parks at this link. This may give insight into what is happening as the fall unfolds in the southeast.