This is a magical time of year as most of the leaves on our deciduous trees and shrubs color up and begin the process of saying good-bye for another growing season. There are literally trillions of leaves, just here in the metro area, even more leaves than dollars of national debt. Those leaves sprouted forth from the branches, twigs and stems of our trees and shrubs as early as March, April, and May. They unfolded to produce beautiful foliage, often green colored leaves, which have worked all spring, summer and fall to cool and beautify our landscape. These leaves are really photosynthesis factories to produce sugars and carbohydrate food to support these trees and shrubs and even produce extra energy so these plants can grow larger and to store up food and energy to make it though the long winter ahead. Chlorophyll is not constant, it is ever changing. It constantly breaks down during the growing season and is replaced with new chlorophyll. In the fall, with shorter days, longer nights and cooler day and night temperatures the connection between the leaves and the rest of the tree or plant begins to absciss or be blocked. The chlorophyll which provides the green pigment in most leaves begins to disappear as it cannot be renewed and we begin to see the other pigments in those leaves that had been hidden by the constantly renewing chlorophyll.
Next year’s leaf buds are already set and carbohydrates have been stored for winter in the branches, roots and stems of your trees and shrubs ready to launch a new season of growth next spring when this miraculous cycle of life will repeat again..
The fall colors vary by species and are greatly affected by the weather we experience each year. Temperatures and moisture levels can impact the intensity and duration of the fall color from year to year. The yellow colors are the result of the xanthophyll pigments and the orange
colors are the carotenoids like those we see in carrots and sweet potatoes. These yellow and orange pigments are in the leaf for the full growing season but are only visible when the chlorophyll that usually masks them over has disappeared from the leaves.
The red and purple colors are the result of anthocyanins. They occur when the sugars that would usually be piped out of the leaves is trapped in the leaves as the abscission process starts and movement between the leaves and the rest of the plant becomes limited. These orange, yellow and red pigments will all break down after a short time and all that will be left are the tannins, which are brown. Some deciduous trees and shrubs drop their leaves quickly; others hang onto their dead brown leaves long into the winter.
The best fall color occurs when we have adequate moisture, bright sunny days and cool nights. We can all enjoy fall color in our own yards, our neighborhoods, at public parks or arboretums like Will Rogers Park or Myriad Gardens. The most spectacular fall foliage in Oklahoma is down in the forests of southeast Oklahoma including the famous Talimena Nation Scenic Byway.
Don’t forget this is a great time to plant new trees and shrubs in your yard. Plant hardy mums, fall asters, ornamental kale and cabbage for color right now in your garden. Set out pansies for color all winter. Plant spring flowering bulbs like: daffodils, hyacinths, crocus and tulips now for great color early next spring. Sow tall fescue seed now for a green lawn this winter. This is a wonderful time to be outside, so get outdoors and enjoy the fall color and do some planting to assure living color for the future.
Rodd's Seeds of Wisdom 